Very good checklist in all aspects, very well thought out.

Only thing I would add to your mixing checklist item 4 after: "Is the stereo signal balanced, or did I pan too much to one side?"

would be:

"Did I check the mix in mono to make sure there are no phasing issues and that everything is balanced when played in mono."

For example phasing problems can be an issue with multiple guitar tracks possibly going through a different fx chain, I've run into it before when layering guitar tracks.
Hard to hear in a stereo mix with the guitars panned, but very easy to hear when played back in mono. Same with an instrument being too loud (or not loud enough), might not spot it in a stereo mix because it has it's own place in the stereo spectrum, but easy to spot in mono.
Fix those issues and not only does the mix sound much better in mono, also sounds better in stereo too.

Lots of guys skip this step, but it's important IMHO.