I could retag the questions myself but I think there might be some linking (from r2d2->r2-d2) that requires a moderator's touch?
A few months back, we had a discussion on tags for Star Wars characters. The consensus then was that these tags were not necessary. Has something changed? Otherwise we should just remove r2-d2, c-3po and whatever other ultraspecific tag has crept in. (There's no moderator tool for this, the tag has to be edited out manually.)
For that purpose, there is something called Tag synonyms, you have enough reputation to suggests one.
DO NOT SUGGEST THE SYNONYM ON THE r2d2 TAG! (It will do the opposite of what we want here.)
You should create the r2-d2 Tag and retag the questions. You will then have to wait for some script to execute before the rep needed to suggest the synonyms is transfered to the new tag.