I don't have TOB and last time I completed the game I reached the XP limit well before the end and so wasted alot of XP points. It is worth using the XP remover or will it unbalance the game?

Warby

IMO using the excap remover will unbalance the game. It will make SOAs ending far too easy which in turn takes alot of fun out of the game. I'd say if you can buy TOB it's worth it.