I would like to see the capability to mark a email in some manner, either by row color or font color or row column so that I know to not delete that email from the MWP table.

I have a high volume of emails some of which I need to keep some on the table for periods of time, I would like to find a way to designate them from the other emails so that when I do a "mark all for deletion" I can easily see them and uncheck them to avoid deletion.

Your best solution might be a dedicated e-mail account that you don't share the address of with anyone. Just forward the messages you want to keep there and delete them when no longer needed.

Since the address wouldn't get spammed you don't even need to include it in the default MW mail checks.

Gmail or yahoo would both work well for a holding account as long as you picked a good unguessable address.