David,
Beware the challenge of a store layout! My local store has a work in progress layout that has some great elements, but it is reasonably "static" in an unfinished state. I put in a bit of work on it with one of hte employees a while back, but we didn't get too far.
I really like your clinic idea. A couple of thoughts I had that would combine the two (and possibly spur business) would be to have a diorama, maybe combined with a contest.
The diorama would showcase a new kit or other new item and the clinic would show how it is used or built (or whatever). If you wanted to add the contest element, you could have people bring back their finished model for display in the store. At the end of the month, the winner would receive something (another kit, refund of purchase price, discount card, whatever).
Congratulations on your new venture. I wish you every success!
Andrew