1. That was indeed a bug. I just fixed this and attached for you a fix unitypackage here.
2. Hmm. I can’t think of any reason for stars to be removed in days relation. The only reason stars could be removed (as far as I know) is if you changed the project name, since the favorites is stored in Unity EditorPrefs in a key name based off your project’s name.
3 & 4. I honestly dont get either of the two errors you see here :(. Hmm What Unity version exactly are you using?