Yeah, while the sharp-shooter sounds fun, I would recommend trying to play with just the Move as well. I think this is more likely to replace regular controls, as it's about as comfortable as holding a mouse upside down while resting your hand on your lap, imho, and requires about as little movement too. You're also less likely to notice any 'cursor drift' as with your hand in your lap you're controlling your 'cursor' relative rather than absolute (looking down sights) anyway.
So far, no Move game has managed to keep the aim exactly right with the direction you point the Move controller in consistently. I personally think this is because currently aiming almost universally only uses the gyroscope. But even absolute controls like in Tumble seem to sometimes experience some drift (that is corrected if you move the controller around enough - there is clearly a type of auto-calibration between the move and the camera).
Best results seem to be if the camera and the Move controller generally look each other in the face, as it were, in my experience (so in my case the PS Eye on my TV looking down to the couch-seats)
