I am trying this mod with a mage protag. and need some info.
1) In order to get the added content do I need to have a mage or will a sorceror do? And is the added content worth it/
2) I am having trouble dualing to a cleric after creating a human swashbucker. What do I need to have with regard to stats , weapon choices etc.

1) Yes, a sorcerer has access to the Expanded Mage Stronghold. However, note that there is powerful sorceress available for a large part of the game; also, compared to a mage, a sorcerer protagonist will probably collect slightly diminished rewards from the stronghold.

2) 15 DEX (which you really should have anyway) and at least 17 in the main attribute of the class you're dualling to. So, in your case, 15 DEX and 17 WIS should do the trick; and while it's not a dual-classing requirement, make sure you get 16 CON. Also, note that Clerics can only use blunt weapons, so don't waste proficiency points. When are you planning to dual?

Please correct me if I'm wrong, as I haven't had a chance to play in quite a while.