We like to play a lot of 10 player FFA. Vasari are so OP with the phase gates, roving starbases, and planet muncher that I am the only person that plays anything OTHER than Vasari. I usually dominate all my opponents until some knucklehead gets the jumper, then it's gg.
I love the Advent. I truly think that they can stop the Vasari. I don't have spreadsheets, none of us are skilled players, and we just mess around and have fun.
But I digress. Here, in my limited scope of endurance, are things that should be given in different forms to each player to fix the imbalances.
1) Moving starbases: Let them all move. VR can jump? No worries. You can research an ability that reduces enemy structures damage/health upon hitting your culture for Advent. Terran can research a shockwave that will shutdown enemy starbases for X amount of time inside it's owned planets.
2)Kostura Cannon: Eliminate the extra phase gate. Allow it to keep it's ability to shut down planetary defenses (did you know it also destroys all fighters in the system?)
3)Give each race the ability to reproduce enemy tech once you capture ONE of the enemies' planets, as long as you hold it. That would solve all balancing issues.
4)Phase gates: 30 minute global cooldown after using one. Tech 8 ability to lower the time by 2 minutes for each of 3 upgrades. Allow each opposing race a system defense that would block phase travel within 2 sectors.
5)For crying out loud, give each race some bomber defense like Vasari's hangar bay phase lock, whatever that is.
6)Every race has a powerful superweapon except the lonely Advent. Nuclear cannons, planet defense shutdown, RAWR. Culture gun.... squirtfail.
"ADMIRAL!!! THE TEC HAVE ASSAULTED THREE OF OUR PLANETS WITH NUKES! Loss of life is total, we've lost the systems!"
"Lieutenant, return fire with the all powerful Culture guns! Maybe we can get them to switch to our side in an hour or so!!!!"
/end rant