Nope it won't effect your current queued site- an "unwritten guideline" is that a site is normally allowed one listing in the Topical branches (Arts/, Computers/, Business/ etc ) and one in the appropriate Regional/ category - of course, this isn't a "hard and fast" rule and there are exceptions to it, but <img src="/images/icons/smile.gif" alt="" />
Don't worry about the Nottingham category not having an editor - there will be editors "higher up" in the tree that will be able to edit the site and the Regional/ categories are usually a bit better maintained than the Topical ones (as people feel "more at home" when editing them). It could even speed up your listing in the Topical category (as your site will have then been 'verifyed' that it can be listed and have a description written for it which the editor in the Topical/ branch could then copy and tweak: saving a lot of time).
