From my years of riding belt-driven Buells I've gotten pretty good at knowing when a belt feels too loose (too tight is another matter unfortunately). Whenever I thought the belt on the Zero felt too loose, a quick check with the Krikit showed I was right. Running the belt too loose is DEFINITELY a good way to strip teeth and eventually snap the belt (Running too tight is a good way to wear out your wheel and motor bearings prematurely).
On the other hand, this is another good use for that $30 track stand I bought from Harbor Freight. Once the rear wheel is up off the ground I can freely spin it and check the condition of the belt. So far, it doesn't seem to have periodontal disease (missing teeth).
From what I've been reading in here, a weekly examination of the belt doesn't seem out of the question. If you follow the MSF's recommended T-CLOCS inspection, you would actually be doing this before every ride but (as a former RiderCoach) I think that's a little on the "Obsessive" side...