You forgot a few critical steps for a full PayPal replacement. Might I recommend:

* Set up a Twilio number for billing support. Play hold music even if your office is closed.

* Proxy transactions to Stripe using a intermediary server in India to match the latency and reliability.

* Randomly multiply totals by 10.

* Randomly forget to call the Stripe API.

* Setup auto renewals. Even for one time payments.

* If a customer has more than 20% in receipts than the previous day, freeze all funds for 190 days.