Do your mods or add-ons require a recompile?
While most don't require you to recompile your store, if a product does need this done it will be clearly stated in the description.
Does the Extra Function Category for BV5 prevent people from purchasing products.
No. It only restricts category content. The products listed (if any) will still show up in your other categories and search results. If it is an option you can modify your search to ignore the desired products, but that will not stop someone from linking directly to them if they know/guess the url.