This is a brilliant concept for a plugin which I'm sure a lot of people will use.
May I suggest the following:
- Instead of a Tags page, a sidebar widget (no checkboxes necessary) akin to the Tags Cloud would be more practical (list or flat layout, Admin selected).
- The results of the Tags search be displayed thumbnail size and in rows (the number of thumbnails per row could be selected by Admin not to break-up the theme layout). IMO, the way the results are shown at the moment, if you have a large quantity of photos for certain tags, the results will span across several pages or on one very long page.