1/2. Why not a private instance for $4/month, accessible only to authenticated requests (unless of course you choose to open up certain routes for GET and/or POST)? Not only does this mean you can use semantic URLs instead of random ones (which helps offset the annoyance of managing API tokens), but you also get a unique domain that you can do things like put behind CloudFlare or another CDN.
3. This is an interesting idea. However, by far the greatest strength of the current implementation is that it has 0 (well ok, very little) explicit state. What's your use case for the semi-persistent producers?
1. It's interesting that you request hosted consumers and not hosted producers (a la for hosting a website). But I see the appeal. It would be nice to be able to set up something like a text notification trigger and not have to worry about it being tied to your own physical machine.
I totally agree about the open source bit. I don't see open source as a threat to a business model here. With something so simple it's going to come down to execution and customer service. As a staunch supporter of self-hosting, after 1 or 2 services it simply becomes too much to manage, unless you enjoy it as a hobby. I just want to get work done without giving my digital self over to the big guys. Even paying others per service doesn't really work, because at 5USD/service (which I paid for a Mastodon instance for a while), it quickly becomes too much money. Part of the inspiration for patchbay was trying to make a dead-simple substrate on top of which I could implement many other things, hopefully saving me some self-hosting trouble.