A couple of suggestions. Since game is more involved I think requiring a turn every two days (with usual exceptions as needed) would make sense, and allow for reasonable completion times. 9 cities is normally used for tourneys. Individuals could also cherry pick extra rules on a per game basis.

How about team play? Or at least pairs for now. Might make game easier to learn (2 heads vs 1), and make for interesting strategy. Unlike other tourneys sharing of ideas between team members would be encouraged.

Spinboldak