I've posted some feedback on the steam forum. In my game the Drengin were far and away more powerful than anything else on the map in terms of the faction power number. When I won the game around turn 220 I was second with around 1000, and the Drengin doubling that. I think I may need to play a bit more, as I am not sure if it was luck of the drawn when it came to their spawn, but I personally think galaxy generation could use some tweaks to even out faction balance. I played on loose clusters Huge. as it gives the most even planet spread in my experience, but still leads to the kind of geography that creates islands and dead ends which really hampers other AI from expanding and challenging neighbors. Otherwise, I really like the extra war aggression and how the AI will do better with research and colony expansion -- these were all much needed to make the AI more interesting.
I also agree, that it appears influence has been cut back a bit much -- how could anyone perform a influence victory and strategy focused on planet culture flip?