I recommend searching the forums for some of your questions. There is a lot of info out there just waiting to be re-read.
As for voiding your warranty? Hehe - good luck. It's a crap shoot any way you look at it. Get window tint and they'll probably void any window warranty issues (streaks on window, burned window motor, cracks, etc). Do a search on 'warranty' and you'll find lots of interesting discussions.