I think the AI in general needs a lot of tweaking. Especially a lot more individualism. This may change with new features but currently all races react more or less the same.
If you build to close they shoot your buildings. They expand a lot in a linear way and they try to grab every resource in reach.
Odd enough, the Thoraxians who are meant to be a very dangerous race ignored me even when I knocked directly at their door. i even was crazy anough and kicked that door down (destroyed buildoibngs from them) and they still ignored me. Until I started research in transedence. That's when they went all out on me and run over me. Holy shit, I never saw such a big military throw in this game until this. When I gave up almost my whole city was destroyed and they only stopped because another race that I couldn't see tried to attack the Thoraxians, shifting the attention of teh Thoraxians to another point.
I excpet Thoraxians more aggressive. But maybe they are intended to be like a bee nest. Mostly harmless until you decide to shake the damn thing and angering all bees inside.