Proceed with launch as planned and validate your market first of all. After you have validation of customer buy-in and market acceptance, when you have time an

Proceed with launch as planned and validate your market first of all. After you have validation of customer buy-in and market acceptance, when you have time and/or funds to spend on your Stripe-alternative feature sprint, setup and integrate a 2nd payment gateway for redundancy. (as per the commenter above whose biz was banned from Stripe for 7 days by the imperfect non-recourse ban-bot) Maybe even choose a different gateway that is more cost effective per transaction for a subset of your global customers, and code your system to route customers payments to the preferentially lower-priced gateway for their country. Then if one gateway bans you, it's not a showstopper and your business is not severely damaged.