How can I view/sort tracks by dated added to REKORDBOX, not date added to computer/itunes?

That tag is persistent across the sync in order to maintain the date added regardless of the source to which it was added.

Best thing I can suggest (if you haven't opened/closed rekordbox more than 2-3 times) is to go and re-load one of your database backups prior to you adding that playlist.

Go to: ~/Library/Pioneer/rekordbox

Find the datafile.edb, rename it datafile.withitunes.edb

Find datafile.backup2.edb (because chances are the datafile.backup.edb also contains your iTunes imports, but check it against the time/date of last modification to see if it was before your import) and rename it to datafile.edb

Load rekordbox and check to see that it doesn't have those tracks.

Perfect. Thank you.