To reiterate Steven's suggestion, I use the 'grouping' tag to split my library up into sections. It is meant for orchestral groupings, but hardly anyone uses it for that purpose. My current 'groupings' are:
· No filter <--- appears automatically when you create the first filter
· Main [rule: grouping is null]
· Jazz, blues and world [rule: grouping is 'JBW']
· Classical [rule: grouping is 'Classical']
· Pop & Party [rule: grouping is 'Pop']
· Progressive [rule: grouping is 'Progressive']
· Other [rule: grouping is 'Other']
An advantage of using the 'grouping' tag is that the shuffle feature has a setting 'shuffle tracks by grouping', so you can queue tracks from across different library sections, but then have them shuffle within each section Eg. all the Jazz and Blues first, then the Pop, then Progressive, etc.
For the editing scenarios you mentioned, if your inbox is empty, you can temporarily drag files from your library to the inbox to work on them. They get removed from the library until you drag them back. If you end up with a lot of tracks in the inbox, you could expose the 'comments' field in the columns selection and make a note of why albums/tracks have been moved there.
But if I've got a lot of editing going on, rather than use the inbox I tend to flag stuff appropriately and use autoplaylists to then list the tracks that need attention. Eg. using the 'bomb' rating, the 'quality' field, and the 'ban' flag to signify different problems, as well as autoplaylists with rules for low bitrate, genre mis-tagging, unrated albums/tracks, etc. I have all these kinds of playlists in a collapsible 'Admin' folder to keep it out of the way of my listening playlists.
Hope this gives you some ideas for your work flow.