For 2, I wonder if there could be a 'wrapper' service (website) around Fediverse that makes it as easy to set up an instance as Slack or Discord. It would still be decentralized, except the service could abstract away the technical bits entirely.
When payment runs out, it emails you a download link to export your data which you can take to another provider, or just start paying again and it starts working again.
I'd send a few bucks to such a site, sure.