Furthermore, does withdrawing the funds to the bank account after the money is received prevent the possibility of money leaving the account thereafter?
You can withdraw the money to bankaccount and cancel any direct debits you have for paypal and delete all acounts in paypal. Then if chargeback occurs, they will give back using paypals money but paypal will come after you for it. If the amount is big enough, lawsuits etc..
yeh ... the chargeback is done from the credit card company. When they pay .. the transaction is still like in a "pending" state and he can ring up credit/debit card company and tell it he didn't do it and was unauthorised -> chargeback on paypal -> you lose.
Get him to send you money through bank transfer and not paypal, then you're good to go