Currently, you can only edit a number (with a slider) in a variable monitor, and edit lists. You can display all types of data in a monitor, of course, but if its a boolean, string, or even ring you cant edit it. Perhaps you could toggle a boolean, edit a string, and add blocks to a ring. This would be so useful for debugging! Perhaps even allow selecting a sprite or stage, costumes and sounds, colors, and much more!
Maybe, the monitors could stay normal, but have a “edit…” option that changes the contents?
I think that would be advisable if this were every implemented, given that the fact that table view is used for lists with more than 100 items is because of just how slow list view is given that it has to be able to edit the list items.
As for the rest of your suggestion, as a workaround, one thing you might want to consider is the BLOCKIFY function in the metaprogramming library. You can use it to blockify (convert to blocks) any data you want (excluding objects, costumes, sounds, and colors; the first three of which make sense, the last of which has an easy workaround). You can then edit the list by hand and set whatever variable you were watching.