I don't look through the BST section that often and from what I have seen I think most of it runs well and should not be changed.
But I will say that in some cases a new thread should be made. A perfect example in my mind is review units FS thread. Now maybe not even a new thread needed but cleaned up. As it is, we are at page 26 (my settings) and only the first and last two pages are in any way relevant. So maybe just with certain threads that get reused a lot, there should be some sort of either cleaning or closing and starting a new. I completely agree with not having more than one active thread. So once everything is sold from a thread and there are multiple pages of posts either clean it or close it and start a new one when needed.
As for actual rule changes, I can only see one change that I would really endorse but is not a huge deal. That is bumping down to just once per 24 hours, otherwise it is all good with regards to the rules.
"Nothing sucks more than that moment during an argument when you realize you're wrong."
I think it is perfectly fine the way it is. Some people re use, some people do not.
If it bothers you that much, then don't buy from the person. As soon as you get your hardware, will you care if the person bumps 100 times a day, or once a year? The BST isn't like other sections, you really only need the first page, and the last page, both easily accessible.