That’s correct I guess you’re “renting the product” and the artiste gets a (very) small contribution for each play, stop paying the rent and the product is withdrawn. Roon will not have access and streaming of Qobuz will no longer be available. Roon software is very clever, if for any reason Qobuz is not available then streaming stops, on reconnection your streaming library is available pretty much immediately.
Not exactly, playback speed, in my experience, is unaffected. However poor internet network connections tend to cause streaming/playback to stop or get interrupted with various error messages (problems with your LAN can have similar effects).
These issues would affect any streaming service of course.