I'm just a customer and have no authority to speak for ib, but as I understand it, you can only withdraw to the account listed in your customer profile, and typically that bank account will be the same one you used to fund your account, unless you have requested a change
1. to move to another non ib account you would need to first withdraw to your bank and then move from your bank to the other broker
2 same as 1
3 same as 1
not 100% sure, I am no expert, that is just my understanding, ib is pretty good about answering any posted questions which concern them, so I would wait until I hear it from the horse's mouth rather than trusting me