I have had zero issues. I did few things that really help. I (did) have only 8 gigs of ram. I recently upgraded my computer to 16gigs ram, a 500 gig SSD, and a GTX 970 (4gigs on it). My processor is Overclocked I3570K @ 4.2 gigs.

I also set my min and max virtual memory to 16 gigs even though I have what would seem enough. This pass around I can tell that Paul and his team did a good job catching memory leaks. I am almost 100 turns in and it runs smooth. 

I ran Insane size map on my 8 gig system on old processor and had no crashes.  Some lag, but nothing horrible.  I didn't go too many turns on that map.  I have another 8 gig ram on order and am eagerly waiting.  Had a crash on Immense and am trying to submit a ticket.  Meanwhile, I am playing with the shipyard, again. 

I hear that the game will support 100 races. Is it? Because this number of them will be enough to fill the insane (I hope). Though it'll have to be pain to create them. I'm alredy searching through all the space stuff I ever played or watched as movie to build up a list of opponents to create. Does anyone know will there ever be limit or it is "take as much as you can carry"?

Obviously your thing isnt a poor computer. Try increasing the virtual memory pool as you have been suggested to do.

Randomizer will also need a lots of stuff like portraits, bacjground, flags and the like to choose from when creating random factions. It will need the ability to randomize colors (when they'll come around to fix that oversight and put a painting tool back in the game). Otherwise we'll be having a one hundred nearly identical twin looking races.