Okay, I've played SoaSE since it came out a few years back and there are still some annoying things, made even more evident with rebellion, that needs to be fixed as far as the AI is concerned:
1: Scouting with their Titan.
Seriously. I attacked one planet with my entire fleet composed of 1 titan, 4 caps and the rest being your usual frigates/cruisers army. Their Titan retreats with the rest of the army, knowing it would be crushed without a lot of reinforcements. Well, for the next 5 minutes, their Titan would actually jump back in the grav well with 2 capital ships and see how thing goes! BUT OH WAIT, AN ENTIRE FLEET WAITING FOR ME!? BETTER RETREAT.
30 seconds later...
HM I WONDER IF THEIR HUGE ARMY IS STILL THERE, LET'S GO CHECK IT OUT
After a few repetitions, Titan goes boom. This needs to be fixed...
2: Knowing when odds are against you.
This one is a little less obvious. Sometimes the AI will attack you with a nice fleet, and you're trying to buy as much time as possible with defenses before your own fleet arrives. When it does get to destination, the attacking army has no way to win whatsoever but stays there anyway! I can't count how many times I've won because I baited some fleet into attacking a poorly upgraded starbase, having my own huge ass fleet sitting 1 phase jump away, ready to kick some ass... The AI needs to know it's doomed and must retreat (without sending their titan to scout every 30 seconds.)