Arranging to pay out money is a whole other level of complexity that I think neither the Subscriptions plugin nor Stripe is equipped to handle. You could do payouts with PayPal, but it would still require a pretty complicated setup for any user wanting a payout (at least I think that’s what I remember from looking at this before).
In other words, I think doing payouts is a $5,000-10,000 problem (probably more with proper tests to have it the same quality as core code). And then working out a tips credit system is probably another $2000-5000.