10 provinces per player sounds about right, but I don't see a reason to cap the number of players. If things bog down in the late game we can slow the turn timer, but I really don't expect this to happen for a long time if ever. Slow timers (especially in the early game) cut down on excitement and I find you get more staling and dropouts with slow timers than with fast ones as people lose interest.
As an example, I have a 20 player game with 11 provinces per player running now on turn 35 and it's not too hard even for the largest players with 20+ provinces, in fact we would probably be doing 2 turns most days except there is always some almost-dead player or another staling.
hako: I didn't know about the problem with Bandar Log before. You should not play that nation, it's broken, I confirmed that the problems still exist in the latest version. Of course, I don't see what's so tough about Kurgi, his attack and defense are both only 0
Turin: I think CB mod uses the broken mod commands, so Mac users are pretty much out in the cold on this one, unless they can play in an emulator or something. Thanks for the offer, though