You have spoken the Words wrongly.
Why do you do this thing? (When I'm asking a serious question.)
1) yes (given the research pops up of course)
2) yes
3) only after ascension (takes a long time)
4) when do you pick up the purity tree?
7) when do you pick up the harmony tree?
1. Right, should be within the first 30 years max.
3. These are just the ME/hive mind versions of paradise dome, they're in a different # since they can be built before capital upgrade.
4. If I have the purity tree option, I also have the at least -20% and as much as -50% starbase influence cost at game start, and those reductions stack additively. If I have space to expand still, purity is usually #3, no later than #5. It is also the biggest unity boost.
7. 1st or 2nd. +25% growth or +33% build speed? Yes please.
However, the unity boost from paradise domes is no better than any other tradition tree provides; I get it for growth speed, and so I don't have to research farms. Prosperity also provides 2 per planet. Adaptability/versatility/diplomacy/domination/supremacy all provide up to 30% with varying levels of ease (diplomacy also technically gives visitor center, for masochists). The only worse one is supremacy for empires without rivals (only +10%) and the better ones are purity (only +10%, but an optional +4 unity per planet at the cost of a tile), discovery (unless your science sucks), and expansion (only +1 per planet, but a hefty cost reduction if you have planets.)
So, if you're always picking supremacy first, and the 2/3 strong ones never, order could be hurting you. A little. But, as long as you're using whatever tools the trees you chose gave you, you should be pretty alright. My list wasn't "I always build all of these" (some are mutually exlusive) but "this is what I prioritize when I have access to it."
For me the problem very quickly becomes that as a FP your expansion rapidly overtakes your unity gen causing your unity timers to exceed 120 months. This means you only get 1 pick / 10 years. 20 picks (2200 - 2400) = 4 trees. This mostly has to do with the immense amount of systems between your planets as you go to conquer everyone, leading to a massive unity penalty relative to your colonized worlds. Do you just dump everything into a sector and colonize everything you can, coming back to the sector(s) later to fix them or what?
My timers were never over 85 months, and even that's inaccurate since the discovery tech bonuses aren't counted into it.
So, if I understand correctly, you do some combination of these 3 things:
1. Pick supremacy early.
2. Go to war early and often.
3. Leave planets you take purged of all life.
#1 is generally not a great option. Even on high difficulties, war is not hard, if your economy is alright. For FP, it's especially bad, since they get less +unity from it, and already have big military boosts; you can conquer just fine without supremacy, so economy boosts are better.
#2 is fine, as long as it doesn't lead to #3.
I just tend not to conquer planets faster than I can integrate them. Conquering space you'll leave barren for decades, as you can see from what you just described, isn't very helpful. Depending on my economic strength, I do one of 2 things:
1. Conquer about twice as much as I can handle, purge half and integrate the other half.
2. Conquer about twice as much as I can handle, and my economy is so strong I can ride 15/9 core systems for a few years as I integrate.
Either way, I make peace when I've reached that point. Integration just takes a few years max, to let 5 pops grow (migration and/or resettlement helps) which is enough to build all the buildings and robots and upgrade all the labs. Then hand them off to my no redevelopment / no robot building sector, and either make war again or settle some juicy planets, depending on how I feel.
