I for myself don't like war that much so i do it only if neccessary. In this case to fight a stronger oponent is not fun for me under any circumstances because it forces me to build fleet and fight. The only exception to this are the endgame crisises. Until then i've build everything i want, my fed is lv 5 and the fed fleet is most likely strng enough to dea with it 8even on 5x crisis strenght). The war in heaven on the other hand is the worst event for me as a example. One option is to stay neutral and loose my hard build federation with most likely 5+ members. The other is to lead the unaligned systems and get declared war by both of them after a short period of time. And if i do not build fleet in advance they are much stronger. This war is in addition a total war and runs a loooong time and cannot be avoided. So no i don't like war and will never like.
I think i should make clear what i understand under "equal power". In my former posts i already declared what i want espionage to do. Equal is for me to have an huge impact on the galaxy. And manipulate empires to fight or befriend each other in my liking is such a thing. A sabotage ship to the right time at an empire fleet (destroying) or megastructure (deactivating for a certain time) is a huge impact as well. Having the ability to split up a federation without a fight is a huge too. It is not necessary to destory another empire directly by espionage or sabotage and thats not my goal. The goal is to control the flow of information and the opinions of each other. And if two other empires fight each other to manipulate the flow of war in my favor. That is what i call equal power. If i'm attacked directly it will most likely do that much. And thats ok. It should be balanced.
There's nothing wrong with not liking war (god knows Stellaris warfare isn't a thrilling time; for every interesting war I've had I've had 10 boring, one sided slogfests). But it certainly can be fun, and since it's mostly a measure of your economic strength, it indirectly involves almost every system and decision in the game, which means it
should be more impactful then things which do not do this (like espionage).
As for what you think espionage should do, some of it seems
far too powerful. You've already mentioned how you don't like your federation being lost if you stay neutral in the WiH; imagine if any random AI empire could destroy your federation at will without you being able to do anything about it. Likewise, destroying an entire fleet (which is a massive economic investment that takes decades to properly set up) without any counter is too much, and it would only matter if you were already at war with your opponent. Other parts seem too weak or arbitrary, like deactivating a megastructure for a short time. This both makes little sense (how do you "deactivate" an interstellar assembly at all? How do you meaningfully damage a dyson sphere, something by definition the size of star, in such a way that it isn't completely destroyed? The fluff for the SCC and the Science Nexus explicitly mentions how secure they are, how does that square with espionage? Megastructures in general are just too big to really be "sabotaged" by anything short of a Colossus.), wouldn't actually mean much (worst case scenario: random AI #52 turns off my dyson sphere for a couple months; I'm 3K energy credits in the hole... all I need to do is sell 50 alloys on day 2 of each month so I don't have a critical shortage, and I'm completely fine. The other megastructures have even less of an effect on day-to-day operations; they significantly affect your empire in the long run, but losing them for a couple of months won't actually hurt any empire that's strong enough to build megastructures), and would be annoying (randomly turning off megastructures with no way to counter would just be a giant pain in the ass, even if it doesn't actually do anything). As for affecting diplomacy, IMO this should be possible, but strictly limited. If two empires have a long partnership and many pacts (or a federation), you shouldn't be able to just make them hate each other via espionage; they know each other too well for that to work. Likewise, two nations that rival each other, have claims on each other's space, and have fought three wars aren't going to start loving each other because of espionage. Where it should work is in swaying neutrals; if you see your hated enemy starting to sign early pacts, like, say a migration treaty, you might be able to use espionage to get that treaty broken before trust rises high enough for them to sign more pacts, like a defensive pact, or if two empires dislike each other because of border friction, you could use diplomacy to smooth that out. IMO, you should at most be able to move relations between two other empires by one "attitude." So if you want two empires to fight each other, you can try and make it happen, but it'll only work if they're already suspicious of each other (and thus willing to believe whatever bad ideas get planted about the other party). If you want them to befriend each other, you can start the process (by moving them from neutral to receptive) or help it along (by moving them from, say, receptive to cordial), but you can't make them love each other if they're mortal enemies, and you can't jump them from neutral to friendly by yourself. Again, imagine if random AI empire #10 causes your close ally who you've been cultivating for decades to turn around and attack you for no good reason. This would not be fun, and would make diplomacy even less meaningful. If, on the other hand, you can see them starting to cool to you over time, you can take steps to counteract that (like improving relations or hypothetically assigning some counterespionage resources to seeing if there's some shenanigans going on there) and even if you don't, they won't randomly attack you... they'll just be less likely to sign new pacts or form a federation.