Reading this diary through a second time with thought I have to say I find myself slightly dissapointed. Becoming the custodian, the shield of the galactic community, should really be a thing that comes with great powers but also with great responsibility. These responsibilities should naturally be impactful enough so that becoming a custodian is not trivial and likewise the powers granted to the custodian should be impactful enough that other members have to consider if they want to grant those powers in the first place. Key word here is impactful. If the resolutions, like the anti-piracy initiative, are only miniscule number adjustments that you won't even notice then no1 is going to care if they pass or not. Where's the fun in that? And if you don't want to get into all the responsibilities of the Custodian you can just stay at the council level and support/oppose any1 who wants to become a custodian.
I know it's too late to propose any changes as the DLC is probably fairly close by now, but here's atleast some concepts and ideas that came to mind (all numbers only rough estimates showcasing the potency the resolutions should have).
Custodianship
Custodian War Effort (5 resolutions)
Border Patrols: -10% alloys, energy and fleet cap for all GC members, these resources are instead given to the Custodian. Custodian gets +25% dmg against crises.
Auxiliary Fleets: -20% alloys, energy and fleet cap tax, Custodian gets +50% dmg against crises.
Support Fleets: -35% alloys, energy and fleet cap tax, Custodian gets +75% dmg against crises.
Battle Fleets: -50% alloys, energy and fleet cap tax, Custodian gets +100% dmg against crises.
Titan Fleets: -65% alloys, energy and fleet cap tax, Custodian gets +125% dmg against crises.
Custodian dmg buff against crises would of course also apply for GDF as it is under control of the custodian.
Galactic Defence Force (5 resolutions)
GDF Patrol Duty: GDF upkeep increased by 20%. GDF fleet power causes scaling Piracy Suppression on all traderoutes of GC members. The bigger the GDF fleet the bigger the suppression.
GDF Fleet Excercises: GDF upkeep increased by 40%. Gives GDF ships small monthly exp gain and new ships added start at Experienced level.
GDF Rigid Training Program: GDF upkeep increased by 60%. Gives GDF ships moderate monthly exp gain and new ships added start at Veteran level.
GDF Elite Task Force: GDF upkeep increased by 80%. Gives GDF ships large monthly exp gain and new ships added start at Elite level.
GDF A.E.G.I.S. initative: GDF upkeep increased by 100%. Gives GDF ships huge monthly exp gain, +20% sublight speed, +10% hull points and +25% fire rate in GC space, admiral assigned to a GDF fleet can't be removed and they gain a special A.E.G.I.S. trait (-33% damage received from Crisis ships).
Getting through the entire GDF resolution path should result the GDF being the embodiment of entire galaxy's martial might, its finest and most motivated voidsmen and admirals, ships and engineers specifically trained to fight the horrors of the void.
The Custodianship mechanics
Make the custodianship take a page out of EU IV's HRE mechanic: Custodian accumulates Galactic Peace (GP) pts (similiar to the new resource that Become the Crisis collects).
Custodian has to defend GC members in defensive war against some1 who is not part of GC.
Killing non-GC member's ships in such a war grants GP as does liberating occupied GC member's planets. GC member losing the war reduces GP pts.
GP can also be gained by killing hostile spaceborne aliens, pirates, marauders, crisis ships etc.
GP is also gained passively every month, depending on how large % of GC members are at peace.
Custodian should keep a certain stock of GP as having low amount of it reduces empire's happiness and trust cap with other GC members (as having low amount means you're not taking your custodian responsibilities seriously) and having it high gives +to Diplomatic Weight.
GP are mainly spent to propose Galactic Peacekeeping resolutions:
Galactic Peacekeeping (10 resolutions)
Custodian Legates: +2 Envoys, +25% trust growth and +50 trust cap for the custodian with all GC members.
Police the Frontiers: -25% influence cost for building outposts, +20% dmg against pirates, marauders and Khan for all GC members, Custodian gets -50% and +40% respectively and also a unique interaction to threaten Marauder factions to cease all piracy and raiding against GC members. Depending on custodian's Fleet Strength relative to marauders, and also a bit on the RNG, marauders might just agree to succumb and thus only raid non-GC members (with increased frequency) or decline in which case Custodian gets a choice to either to go to war against the marauder empire they threatened (war goal is to annihilate all marauder stations, results the Custodian getting GP and opinion and trust boost with GC members), if Custodian chooses to remain passive it results in loss of GP, trust and opinion with all GC members.
If all marauder empires have either been destroyed or have agreed to not raid GC members, then the Custodian gets a +15% Diplomatic Weight bonus.
Intervention Act: Custodian can threaten a war between 2 GC members to cease immediately, results in a white peace if both sides agree and gets GP. If one side declines Custodian joins on the side that agreed. If both decline custodian gets a choice to either to go to war against both empires (war goal is Show Superiority, results in the first war to end in white peace and Custodian gets GP), if Custodian chooses to remain passive it results in loss of GP, trust and opinion with all GC members.
Fortify the Frontiers: -15% cost and +15% speed to upgrade starbases on border, +10 Trade Protection for all GC members, double effects for the Custodian. GC member hiring/having Marauder Mercenary fleets or leaders if at war with another GC member cause being in Breach of Galactic Law. If Custodian has a Starbase on every border they gain +10% diplo weight bonus.
Watchpost System: All GC members gain +5% trade value and +5% sublight speed in GC space. The Custodian gains a special Megastructure they can build; A watchpost. Costs 1000 alloys and can be constructed in any GC member's space. A watchpost acts as a shipyard but for repairing only, it doesn't produce any ships. It also gives the Custodian sensor information as if it was part of their empire (so the system + all the adjacent hyperlanes jumps depending on their tech level). Once the Custodian has established one Watchpost for every member in the GC they get +15% diplo weight bonus.
Peacekeeper Act: All GC members become allied to the Custodian. If a GC member declares war on another GC member then the Custodian joins on the defending side. All GC members also gain max +10 stability on planets scaling on the % of GC members at peace. The Custodian gets a +25% diplo weight scaling on the % of GC members at peace, and the passive GP gain is doubled.
Leviathan Termination Initiative: +15% dmg against leviathans for all GC members, doubled for the Custodian. The Curators enclave gives all their information about leviathans for free for all GC members, and also gift the Custodian a special ship component (think of something cool here). If no Leviathans exist in the galaxy then all GC members get a permanent +10% happiness/job output boost and in addition the Custodian gets permanent +15% diplo weight bonus.
Consolidate Power: All GC-members become vassals to the Custodian. The vassalage is special one (Grand Sectors or something) where the Custodian can't integrate any subjects. Grand Sectors can expand and retain their diplomatic independence to other Grand Sectors but not to other non-Grand Sectors. Grand Sector that is in offensive war against another Grand Sector is in Breach of Galactic Law. They are also protected by the Custodian but are not called to Custodian's offensive wars. Grand Sectors gain +20% dmg against Crisis. Custodian gets +5% diplo weight from each loyal Grand Sector.
Establish Galactic Administration: +1 influence, +1 envoy, +20% diplo weight, +60% Administrative Capacity, +25% trust and opinion growth, +50 trust cap for the Custodian with GC members.
Reform the Galactic Senate: All GC members are integrated into the Custodian empire. Launches an Event to decide the government form and civics for the new empire (can also just keep the old ones). Temporary happiness bonus for pops of empires that had high trust and opinion with the Custodian prior to integration, happiness malus for those who didn't along with high stability debuffs. Strong roaming pirate fleets (representing rebels against the new empire) might spawn in areas of unhappy empires and if too many empires had bad opinions on Custodian the Event might trigger a civil war where those unhappy empires immediately break off and declare war of independence / war against tyranny
Edit: adding a little commentary here on the Galactic Peacekeeping resolution path and reasoning for certain effects. As the Custodian's purpose is to act as the protector for the Galactic Community they should have means to lessen the chance of coming to blows with GC members (example; being directly attacked by a GC member) which where the 1st resolution comes to play. Having the envoys to throw around keeping up good relations to other GC members lets the Custodian to focus on external threats.
2nd resolution helps GC to fill in the empty expanse and fight off marauder raids while having a strong Custodian can stop any raiding towards GC members (making belonging to GC more enticing).
3rd resolution gives the Custodian power to act as a referee in disputes between 2 GC members. Having members waste their fleets in petty wars is surely dumb when Fanatical Purifiers are at the border, right? While agreeing to white peace might be disadvantegous declining the Custodian's intervention is a risk, since if the other side of the conflict agreed to it then you suddendly have also the Custodian to fight...
4th resolution helps GC members to stabilize their borders with bastions and trade protection helps with smaller trade routes. Disallowing use of mercenaries against other GC members brings stability and predictability in GC power balance.
5th resolution helps communication and travel across the galaxy but also enables the Custodian to build a vast logistics and intelligence network. The Custodian can keep up with the fleet movements across the galaxy and deploy their peacekeeping forces safe in the knowledge they'll have a front-line station to repair at.
6th resolution increases stability within GC as any agressor has to account the Custodian being on the opposing side. +10 stability is a nice bonus which further entices GC members to avoid wars, while Custodian getting big +diplo power buff is another reason for them to try safeguard peace.
7th A carrot to get rid of remaining Leviathans, supported by the Curators. Having cleansed the stars from gargantuan beasts and fearsome constructs the population across the galaxy will sleep better trusting the fleets of the GC to keep them safe.
8th GC members lose their diplomatic independence outside of GC, though they can still do it within GC (in wars the Custodian is still on the defending side). Let the Custodian handle all that is outside of GC borders. Also everyone gets some buff against Crisis so its a good deal, right? What could possibly go wrong?
9th blatant powergrab. Preparation for the last resolution, very much a step no1 but the Custodian wants to take. But can the senate stop them anymore at this point?
10th big payout for a long and difficult journey. No one wanted the Custodian to get here but at some point it became impossible to stop. If the Custodian played their cards right their empire sprawls across the galaxy, but if they were too hasty in their rise to power they might see it immediately splinter as rebel ships, leaders, planets, fleets and entire sectors break off to oppose them.
Overall the Custodian resolutions should give the feeling that a proper Custodian brings universal stability, unity and peaceful prosperity to the galaxy, but be careless giving them power and they might end up having so much diplomatic weight from all their accomplishments, the finest fleet (GDF) in the galaxy and such web of alliances that you can't stop them. Not in the senate, not in the field of battle.
Diplomatic Victory
If the Custodian manages to pass Reform the Galactic Senate resolution, all "rebel fleets" have been destroyed, all civil war empires have been defeated and integrated and a Crisis has spawned and been defeated then the Custodian wins a Diplomatic Victory. (Since Become the Crisis already introduced a Monument Victory I think we can add more options, especially the kind that rely more on the politics side).
Basically make all the Galactic Peacekeeping resolutions be something that makes the custodian(s) and the GC members to want to progress them to a certain point but also make the non-custodians wary of giving in too much as the Custodian can really start getting out of control with the extra diplopower from the resolutions.