(Turn 150) Well, the game just crashed for the second time so seemed like a good time to stop and post some comments. Same Game parameters as before (insane, abundant, 10 majors, all minors, challenging).
Both CTD have been in the Diplomacy UI: on Turn 124 the game crashed while trading, on turn 150 it crashed opening the diplomacy UI. Trouble tickets with files submitted.
The good news is the game is starting to be so fun that I don't want to stop to post comments or submit trouble tickets (but I still do).
More good news, with this build the performance is much improved. GC3 is using about 4.9 GB of RAM (was using about 6.2 GB last build), in-turn CPU usage is down to about 17% (was 33%).
Even more good news: no ridiculous colonizing by the Drengin.
Pirates: I like them. I think they should be more aggressive early on in attacking colony ships and constructors. When I first encountered the pirates, I created two kinds of colony ship: one unarmed for closer worlds and one armed to survive pirate attack that took twice the time to build. The AI did not do the same, using only unarmed colony ships. Yet, the pirates didn't attack and the AI got an early jump on colonizing planets until I figured out that the pirates wouldn't attack my colony ships. Overall result: no appreciable difference in the number of worlds colonized by the AI. Me, I want pirates to act like barbarians in Civilization 5, attacking anything they can see. That would act to slow expansion for all races, and force all players (including the AI) to have armed colony and constructor ships. The pirates did attack shipyards and starbases.
Bugs:
This one is a first. I exited the game and tried to close Steam. Steam popped up a message that it was trying to synch. I walked away from my computer and when I came back, this message appeared, but GC3 wasn't running.

I invaded and conquered a world that already had the red unhappy face from being within my influence before I conquered it. Several turns later, the world still has a red unhappy face even though it is deep in my influence territory.

I'll write more later. I want to get back to playing.