Ask HN: Checklist of functionality for a basic SaaS app

I want to offer a subscription using stripe on my rails site. What are some basic things that I'd want users to be able to do. (stupid question, I know, I just want to make sure I don't miss anything critical when handling people's money)

So far I have thought of

* Secure connection (SSL) * Sign up for service * Cancel service * Modify subscription tier * Dispute charge? (Should I handle this, or does stripe do it?) * View historical charges (Same here, does stripe do something for this or should I handle it?) * Modify Payment Details (eg: CC expired, need to update to new one)

tl;dr: what's considered feature complete for basic Software as a Service subscription via Stripe?