I also have issues 1, 2, 3, 4 and 7. On both Macs I've used the editor on. Across a few versions of OSX, all updated to latest versions.
I wouldn't say it's unusable. I've just learned not to do certain things (like drag and drop).
I also save everything after every step (for example, if I'm auditioning 5 profiles in the slots on the Stage, when I edit the title I save it (Can't recall the exact button name without it in front of me, but "save performance"). When I am happy with that profile in slot 1, 'save performance'. When I'm happy with slot 2, 'save performance' etc etc. Once all five are filled, I save the whole performance to a local folder.
I'm glad someone else has mentioned these, because they're annoying and I suspect common. I'm sure I've reported them in the past. It's about time they were fixed.