I find it amusing that a VoP character can't administer a dying friend's potion of cure light wounds to him if he wants to keep his powers.
The feat specifically says that you can wear simple clothes. By simple, I take it to meaning non-magical and non-extravagant. If a VoP character can't even carry a weapon as part of a disguise, then how is he supposed to carry any treasure he finds back to town to distribute to charity? Especially if he's a lone traveler.
The feat mentions that you can benefit from magic items used on your behalf. I don't see why non-magical items shouldn't apply to that either--If you can drink a potion of cure light wounds a friend gives you, why can't you wear a disguise he gives you? As long as you give up the disguise as soon as you're able, there should be no consequences.