How to stop or control a category or sub category from showing on latest items, but keep in search. Say if I only want the For Sale items to show in my latest item section and nothing else , or my Boat items, etc.

@Sparky
You need custom search engine for that, can be found ie here:
https://forums.osclasspoint.com/ideas-improvements-and-tips-24/ad-redirect-_-to-via-htaccess/msg24427/#msg24427

Or use query item functions:
https://docs.osclasspoint.com/display-only-certain-type-of-listings