It's a bit pricey.
No I used to think that too but it actually sucks mega balls
http://xtremegrip.com/SportsGear.html i have a package of it sitting right next to me for my snowskate
This has already been done.
Myself- i would just rather use griptape and i think deckpins would just make the deck weaker.
I guess BMX style riders would like them though. Although they have already been made. Pretty sure TSI did some of this stuff some time ago.