Mike Napoli is kinda what I'm hoping to see from Lavarnway, but then, Napoli is a better catcher than he gets credit for, his issue has been how to preserve his unlimited power potential, rather than any deficiency of skill, and I see Lavarnway having much the same controversy as he goes through his big league career.
Not only is his bat elite, but while his catching skills are raw, there's nothing stopping him from improving them in the big leagues the way Tek did and Salty is doing. No one remains a snapshot of what they were when they debuted as a rookie, and while Lavarnway's defensive form is not great now, I see no reason he can't improve on it. He does have the talent to get much better if he can put it together.