ok buddy, for starters the spacebar doesn't bite.
#2- don't use pop cans or anything aluminum unless it is annonized o whatever. It releases nasty chems and the paint in popcans can't be that good either.
#3- eating doesn't do shit as far as I know.
#4- Vaporizers are the best way to get the most for your money as far as gettting the most thc and shit.
#5- I don't know what's taking you thrity minutes unless you are smoking like 4 buds or something.
#6- for bongs got to grasscity.com and ask once on their forums, and you will find everything you need.