Thanks for giving this so much thought!
My impression is that it would be undesirable to embed the UUID in the filenames. Both because it is messy, but more importantly because of interoperability, which is part of the core philosophy of Obsidian. If we use these files/folders with other apps - either at the same time as Obsidian, or after migrating away from it for whatever reason - the UUIDs will surely mess things up tremendously.
It was suggested above that a UUID could be embedded in the YAML - that seems to me to be the most preferable way to do this as it wouldn’t really create any clutter at all (it would even be “hidden” in preview mode) and should maintain interoperability with other applications and the file system.
As for your three questions
- This thread is that feature request. I’m sure the Obsidian devs are focused on many other things right now, so this is unlikely to happen any time soon.
- and 3. seem to be the same thing to me. If you are able to make some sort of plugin that could implement this functionality within YAML, I’m sure it would be tremendously appreciated by many people. It could also provide a starting-point for the devs to bring something into the core/official code, if that is something they decide to do someday.