Patreon does accept Paypal payments. You will find it there on their Patreon link. Posts like those are always public.
I saw that too but after I logged in, it still asks me for my card details. This happens on subscribe star and pixiv fanbox too.
Ah okay. Yeah you're kind of screwed there. Oh well, with enough time the game will be finished and available to play. I'm also pretty sure that the game will be updated on Steam whenever they get around to it.