Wow, Thug you are amazingly incompetent.
Move your capital to a planet NEXT to a star. A jump from star to star only counts as ONE movement space.
I had an empire spanning 7 stars and 64 planets - and not one with a max allegiance less than 60. Just because you don't know or test the scaling doesn't mean its not there - and if your a galaxy spanning empire you should be BUILDING some defenses. Rebels are a laughable threat.
SEcond off, increase fleet cap? What? You want to make your defenses even more laughable? You can have a larger defense fleet, but they can have a larger attacking fleet - and you don't get any more static defenses. Idiocy.
I just won a game against 9 hard computers on a random huge map - AS TEC. You can't bitch about these things. Just because your not doing them right doesn't mean it can't be done. If you research more supply cap than you need, YOU ARE SCREWED. Only research more fleet cap when you need it. You need that income. You can't just tech up and ignore the expand/exploit aspects of the game. Take one system, hold it, fortify it, move to the next system. Now the only place you have to defend is your STAR.... Repeat.
I had three fleets. Two for expanding, one for defense. Station them by your star and you can get anywhere fast enough to hold out (especially as TEC with your shield and defense tech.). Anyone jumps into your home system, your right there to greet them. With adv. PSidar anyone jumping to any of your other stars (two jumps remember guys, between stars only counts as one) you know BEFORE anyone jumpts to one of your other systems, you can start your fleet moving before he even arrives.
I couldn't EXPAND when I had four computers hit me at the same time but I COULD hold. They can't attack you forever, their credits will wear out, hit them when they retreat and keep hitting them, then when they hit you again, hold and repeat.
What you are missing is the fact that as you get more planets you get less income. All you are counting is the fleet upkeep costs, you arent counting the allegiance corruption costs. The more planets you have the less and less income you earn. The further away planets are from you home system (I'm talking about *far* away not one jump I'm talking about a game with multiple stars)it can get to a point where these planets are bringing in no income.
Care to explain how I was making 214 credits a second AFTER the 75% off the top for supply cap then? Play well. Like REAL LIFE a huge empire is dependent on commerce JUST as much as taxes to stay above water financially. As the TEC finance is cake. Especially after the endgame researches.
And thats playing as the TEC or Advent, as the Vasari with the phase gates it should be cake to move your fleets around.