Does the RTP of a casino affect the payout speed?

No, it doesn’t, as this is simply the amount that you’ll receive after prolonged gameplay.

Do faster payouts cost more?

No, but there are some casinos that charge more for the use of particular banking methods, but this has nothing to do with the speed.

Do more payment methods mean that the casino is better?

No, this is a case of quality over quantity, as a site might have 20 payment options but this means nothing if it takes 16 days to get to you.