Oh yeah, Bjørn has the right idea there. The game would focus on the domain level... with adventures being more freeform. Class and level are what counts, not feats, skills or spells.
I intend to expand slowly, if at all. First plan is to get 10 players and have a turn every 3 weeks. If that's too much, I make the turns slower. If I'm ok with it ot if it's easy, expand to more players or a faster turn ratio.
The point about guilders and mages needing competition is a good one. Keep in mind that Ilien is a mage domain, as well as Endier is a guild domain. So... actually there are 2 guilds, 2 mages and 3 temples. My hope is that it's enough to give competetion. The guild and mage that are there are partly because they are forced to interact with a ruler. Caine is the court mage of Endier, PCE the guild of Ilien and has heavy Khinasi connections. They should have something to do, other than compete for resources.
I was actually considering to give each of the temples, guilds and mages at least one province each, so no one stands without land. Having a piece of land makes the game more fun, for me anyway.