Actually, an IoP should not have Refinement. A Staff or Robe IoP with +2 Rebate would give 3 Refinement for the Price of one, and it would be difficult to keep track of what the refinement went to. A GM has the ability to accept or deny any non-Creature Feature power from being used as an IoP, if they so choose.
Also, an enchanted item is a seperate item, not a modified tool. I'd say no on that.
I wouldn't put all of my eggs in one basket anyways.