I want to know why Sergey doesn't use capital letters in his email! Is there a reason for this?

Yes, he did wrote this from his iPhone. ;-)

iPhone would have automatically capitalised several of those words.

This was a joke. I guess he use a Nexus anyway.

I wish there was a non-JS version of Stripe Checkout. Rather than throwing up the modal window, I'd prefer to redirect my users to a Stripe hosted checkout page where they can make payment and we can deal with it via webhooks. Similar to how PayPal works really.

Currently I'm integrating with the API directly to do this but I'd have preferred to use a page hosted by Stripe, especially considering they are starting to open up to other payment methods.

As a buyer, I hate when pages do that. It jolts me out of the smooth experience of buying a thing. Since I've never done a PayPal integration, seeing the PayPal logo as part of that experience is a big chunk of the reason I believe it when other programmers say that PayPal is super-annoying to integrate with.

Stripe would need a page that doesn't have its branding but instead only has yours.

Stripe defers to partners that handle the checkout process. One example that I use personally is Plasso.

Which you have to pay another 3% on top of Stripe's fee.

Well, Google doesn't even support OpenID anymore (at least not the traditional version).

https://developers.google.com/accounts/docs/OpenID

How many contact forms have you used where your message is printed via WWII equipment? ;)