So I just thought it would be a good idea if, when looking through showrooms, we could choose categories to exclude from our browsing. 

For example (and this happens a lot to me), a user says, 'Look through my showroom but don't touch anything under NFS'. I find it really tedious to have to look in that category and try to remember what's there so I don't ask to buy it. :L If I could just choose to look in all categories except for that one, I'd be very happy.

Maybe it could be like in the new pet search, when you can CTRL-click to select multiple categories to look through?