Bear in mind that the Vow of nonviolence and the vow of peace severely crimp the style of your other party members. They will not be able to kill anybody even accidentally or they take a penalty and you may even lose your feats if you were not seen as taking enough action to prevent it. It will end up turning you into a version of the arcane stupid paladin

You will also become completely useless in the event that a creature is warded against mind affecting spells, being good just for a haste spell that you could have cast anyway.

I guess you could take the vow of Poverty, beguilers don't need equipment, though it does hurt them, though at least then you don't directly hinder other party members.