You're also insinuating that any subreddit that hits critical mass becomes low quality.

That seems to be pretty much the case, there might be a handful of strictly moderated exceptions.

One of my favorite aspects of Uber is that the tip is factored into the price. Please consider just adding a $1.50-2 surcharge and specifying that the tip is included.

Alipay payments will all be nominated in Yuan (RMB). How does Stripe convert this back to USD? The laws of converting currency in China are very restrictive.