Zoneless is completely independent of Stripe, you do not need Stripe approval or a Stripe account to run it. We have some beginner guides in our docs for handling topping up / exchanges. I use Kraken+, which is about $5/month and removes trading fees.
for keeping regular payment processor for checkout....is that stripe? aren't they looking and evaluating your marketplace and then saying yes or no still ? or do you mean to use a high risk processor?