There should be a way to integrate RSS with a payment model. People should be free to get content they want in any app of their choice based and still be able to pay for it.
Hidden RSS Urls already exist. Publishers are just lazy to implement it.
There is. It's called Basic Auth and probably every HTTP library supports that.
There are ways. Lots of podcasts etc are RSS and behind paywalls. Agree we should make it easier and companies are starting to pop up that empower and enable the distributed internet rather than destroying it, even as spotify is making major moves in the other direction.