Three things to say about this:
Instead of marking 99.9% of your tracks as 'OK', why not use the 'bomb' no-stars rating to just mark the 0.1% of the tracks that need replaced or edited?
· You can toggle the bomb right in the main pane or now playing list by clicking just to the left of the star-rating graphic.
· You don't need an extra column if you already have the rating column enabled. Nor a custom field.
· You can use a hot key (ctrl alt 0 for marking the bomb, and ctrl alt - to clear it).
· You can create an auto-playlist or library filter to list the tracks with the bomb rating, so you can methodically fix them.
You can optionally use the 'ban' marker to prevent these tracks from playing until you fix them.
You display the love column, and then shift-click in it to ban a track. Or you can use the player 'love' button. Or a hotkey.
There is a tick-mark column already that you can display as a column. You can toggle the ticks right inside the main pane (although not in the now playing list, because it uses the same column space as the skipped tracks markers). It pairs with a right-click menu option to 'select ticked files' and 'invert ticked files'.
You have to be careful not to click on the column header, because it will clear your ticks.
Also, you can't bulk-tick. Only one track at a time.
Type the word 'ok' into the 'Grouping' field of a few tracks. Then create a virtual tag with the formula:
Search google for a 'ascii tick' and copy/paste the symbol into the formula in place of where it says [ASCII Tick].
When you display the virtual field column, it will contain a tick next to the tracks which have 'ok' in the grouping field.