Seilore, I have 5 or 6 extra AI that i created for the Larger maps. I cant imagine playing with 30 on anything smaller than Excessive. I see now why you are having performance issues.
I am closing in on turn 200 last night. When I found some things that help prevent crashes. When I get ready to hit the turn button I center the map on where i want to look, this can be anywhere. I then hit 'turn' and as long as I have not 'idle' ships or shipyards it will 'process' data. I dont touch anything and it will take its sweet time using all four cores which are pumped up to 4.2 ghz as fast as it can. This is now taking a bit of time, last night with all factions and minors revealed and my ships all over the map, it took nearly 50 seconds before it clicked over to turn 198. Once the turn counter changes I can do whatever I want. I have seen issues where I will have multiple battle viewer fights with Pirates via survey ships. This will sometimes bug on me and Ill get a 'blank viewer'.
In these cases I have been saving ever turn and again prior to hitting turn. I just reload and keep going. No hard crashes so far. The AI itself seems to be doing very well with diplomo and defending itself so far.