1. When you start a campiagn with BI.exe you can't start a Imperial Campaign or play historical or custom battles, but you can start a provincial campaign. And then you can choose the campaign from in there. Someone has mentioned how to make it so you can play custom battles and stuff somewhere in here.

3. It does improve AI I find. Carthage invaded Sicily and laid seige to Capua in 271 of my latest roman campaign. on VH/M