Post Counts and disabled categories

[Light Inspired]

I have a question. Is it possible to delete threads and not have members lose their post counts? There are some old threads from the beginning when my forum belonged to different owners that I want gone but I know members value their post count and don't want to lose them.

Also we now have workshops. They are all in their first run but when they start other runs and I have to recreate the category what should I do? Just disable the previous workshop since it's over? I'd like to delete But then that will reduce post count. I also don't want a year from now 10 business 101's that don't need to be cluttering up the system and taking up space. Thanks