Shopify doesn't allow Stripe, they force you to use Shopify Payments which I have no interest in using, they set their own rules and guidelines that I do not approve of.
For one, Payouts are 7-days in arrear where as with Paypal it's instant. Second, Shopify just started with this processing thing and they are amateurs at it, support has been horrible and they also keep changing their rules and requirements since this is all new to them. The shopify payments team also does not get on the phone, just email, i try and stay away from companies that do that. The irony is paypal just did it to me...