Hey, members accounts can last from friday night to monday morning regularly from my experience - If you're f2p expect to be banned the following day though...
Well you're taking a step in the right direction.. You've just got to keep testing till you find what works best for you; Sometimes it's not about how long the accounts lasts, it's about how much gold you're making in the time you're botting.
So when it come to PayPal, it can still be charged back if the owner of the PayPal account claims it was Hijacked and that someone else made the payment.