Re: Rant: maybe I should have taken up the guitar instead !
*Maybe* if you brought in your own heads to swap out, they might let you try switching them out. I COMPLETELY understand why they're not willing to crack open a bunch of new heads just so some potential buyer can try them out on a kit. It's an expensive gamble!
Plus, if you re-tune the drums, there's the possibility that you might damage the heads, and even if you didn't, someone would have to re-tune the drums after you leave (or just leave them completely in a horrid tuning state, like Guitar Center...). The only time you can really get away with this kind of behavior is if you know the people that work at the store very well, and they know, beyond a shadow of a doubt, that you are serious about the purchase...