Just some ideas that come to mind. I don't know how practical. Would he be willing and able to follow a strict rule "never give your bank account info without

Just some ideas that come to mind. I don't know how practical. Would he be willing and able to follow a strict rule "never give your bank account info without me"? That need should be a rare occurrence. As for credit cards, maybe you could set up an account for him and don't even tell him the card number. Sign up for everything legitimate yourself, Netflix, Amazon, etc. If those accounts need to be updated for whatever reason, he calls you, just like with the bank. And then if he insists that he still needs a card for one-off purchases, give him a prepaid card with limited funds, or "virtual number" that you can change. That way if it gets compromised he has a lot fewer, if any, places to change the number.