Op has a block feature to prevent specific individuals from posting in their thread.

I would vote no since I could see this getting abused in a number of different ways. I doubt something like this will be added.

This has been suggested before and the answer is no, any user in good standing is allowed to post anywhere in the forums. There are post blocker scripts that are allowed and recommended.

You've been here long enough to know better.

What would this help across the site? How would the quality of the user's experience improve with this feature?

no