Thanks for the detailed report, much appreciated!
Note sharing worked. Any selected note, when shared, can be viewed as a web page. I appreciate this is very new and being developed but notes are currently shared without access control.
I don't expect this to ever be any different. I feel supporting a password wouldn't make sense because the password is the share key (the URL ID). I guess if someone requires extra security they can always send a part of the URL via one channel and the second part via another one. Share keys are a 32 characters nano-id, and it would apparently take "more than 1 quadrillion years needed, in order to have a 1% probability of at least one collision", so that sounds secure enough.
However there does not appear to yet be a way to "unshare". Is a share link permanently live?
Yes this is missing, and I'm planning to add this soon.
There does not appear to be any indicator yet in the client that a note has been shared.
I'm planning to add this to. I think I'll add a place where you'll be able to see all your share notes and links so that you can easily unshare them if needed.
Also, if the same note is shared again a new url is created rather than the existing one reused.
The reasoning was that you might want to share a note with user 1, then later on the same note with user 2. After some times, you decide to unshare the note from user 2 but you still want user 1 to have access to it. By creating new share links every time you basically have more control over who can access the note or not. But maybe I'm overthinking it, I'm not sure yet.
If the option on the server to delete all user data is used (items > delete all) , all data is automatically deleted from the client even though failsafe is set on the client.
Failsafe is not active for Joplin Server and I don't think it will be since failsafe requires knowing in advance how many items are going to be deleted. By Joplin Server supports delta sync so we can't know in advance what changes will be apply, at least not without a performance hit. Probably I'm remove this "Delete all" button at some point, as it's there mostly for testing.
If a note has been shared and later the server option to delete all user data is used (items > delete all) , an error of "no id provided" appears (see below) and the user is logged out.
Indeed it looks like the bug found by @thelazyoxymoron related to share, that will be fixed in the next version.