Can I take a save game from a computer with the xp cap removed and put it in the save folder and load it in a game without the cap? I just got to level 20 with my monk, would it bump me back down to the max? or would it remain what it is?

Monks can get to level 20 without XPcap remover IIRC.
But if you are beyond 2900000xp you should get lowered to that number.