I'm not sure if it's possible with this particular setup, but I think adding a basic set of topic prefixes/suffixes would be a good idea. Basically stuff along the lines of 'MT - Open' 'MT - Closed' 'FT - Open' etc.
Making this search able or filterable would make it a lot easier to filter out topics when searching for an RP to join. For instance, if I could get the forum to display only 'FT - Open' I would be presented only with open, FT RP's.
While not perfect, since NSG does have more techs than the basic MT/FT, I do think this would be a good idea.