We currently don't support payouts via Stripe. It's not something they support so I'm not sure when, if ever, we'll be able to do it. We do support direct deposit for US bank accounts but due to the additional overhead it's only for sellers above a certain volume.
As for the credit card denied error, I would make sure that there's nothing in your Stripe account settings that might be preventing the card from being accepted. Did you try buying your game with your own credit card to see if it went through. (You can refund afterwards) If you do want help testing the integration we can step through it, send us an email to support@itch.io.