I'd recommend reading the FAQ abit higher up in the list.
To your questions:
1. This is not a historical mod, however it is probably the best fantasy mod in Warband. (I think so)
2. The map is made of the old kingdom of Pendor (meaning the Devs of the mod made their own, you wont find it elsewhere).
Some of your answers will be answered in the FAQ, a little digging is required.
BUT
in short. There are 5 different Factions.
Fierdsvein (resembling the Nord), Ravenstein (Think scottish culture), Empire (think greek/roman style), D'shar (Think nomadic), Sarleon, (european medival). And then you have other smaller cultures, knighthood orders, invading armies, that may or may not be that happy to see you.

I said its the best fantasy mod, but it is also ment to be played by experienced warband players.
I've found though that when you first have downloaded and begun playing it, other mods seem to loose their charm.