For clans, I'm thinking there would be at least one or two large ones in every province Perhaps three, in some cases. In Cyrodiil, being the central province of the Empire would likely have three, one in the southeast, one in the southwest, and the Bruma clan. Valenwood, being the central province of the Dominion (in geographical terms) would also likely have three. Some provinces may have only one large one if it is in a central location, though it would have a larger population. Regular packs would of course be all over the place, and there may be small groups of packs collected in other places as well. It is Meesei's goal to establish lines of communication with the other major packs in each province, then attempt to expand out connections from there. And of course, there are also other followers of Hircine who are not actually lycans. They will play a role in the war as well. 

I haven't seen anything that says Argonians definitely cannot have children with other races, so I'm inclined to say yes. It's not like races in ES evolved like in reality. They were created by magical means.