You can kludge #1 vertically by using a virtual tag. I have my MusicBee set up that way:
To set it up:
1. Go into Preferences > Tags (1)
2. Click the button under Custom Tags where it says "Define New Tags..."
3. Give your virtual tag a name that makes sense to you.
4. Enter this formula: $Group($Sort(<Artist>),1)
5. Repeat for any other tags you want to be able to use this way, just changing the name and the tag in the formula.
6. Once you've saved your new tags, you should be able to call them up in the track browser.