In mid-December, shortly after this thread began, I removed CPF3 from my PC with some help from the earlier posts. Cleaning up took most of my PC skills, and I vowed not to try CPF again until the uninstalling problems were resolved. Hence I have been monitoring this thread.
Here we are, 6 months later, and it seems that Comodo developers have totally ignored the tales of woe described herein. This is despite that fact that Uninstall and ReInstall is usually part of fixing most CPF malfunctions.
I have used CPF's main rival, Online Armor, for the intervening period without any significant problems. It is worth mentioning that until recently OA Free needed to be uninstalled, prior to upgrading to a newer version, which was quite painless.
It surely seems that there is no reason to change my decision.
May I sincerely congratulate USSS and other helpers for their patience and dedication in providing support to Comodo.