Early hosting would be as fast as people were comfortable with (probably for the first six to ten turns, where everyone is essentially 'setting up' their expansion), but that could easily be 48h quickhost. After that, slowing considerably, probably to 96h or 120h. It would be a very slow game by the standards most MP players seem to prefer, but I think it will need it.
Depending on player population I was hoping to convince people to get something written once a fortnight, which is roughly once every three turns. I'm not necessarily asking for AARs (though they'd probably be a big part of it) but just something that exists broadly within the world of Dominions. It could be an entry in the diary of the Prophet talking about the nation's activities (if it's from three turns ago it's not exactly going to give much away, after all), it could be a discussion of battle plans between troop commanders and mages. Consider something as simple as this one, from
Caelum in the Dominions 2 game 'Yarnspinners'
I think initially it would be easiest to either just have people shove them on here or use the old wiki from the Yarnspinners games.