yeah that home button issue also happened to my phone. sometimes its not sensitive sometimes its over sensitive, it detect like i push the home button twice instead of once.

yesterday i was tethering my internet from IPhone 3G using 3G to my laptop for half a day, until it sucked all the battery power dry. meaning that usb charging thru laptop is not enuf to cope with the 3G power needs.

download those 'battery level' apps and they will tell you how long can you play games, watch videos etc with a full charged battery. i think 4 hours for games is quite normal. if u are a heavy gamer then i recommend u get a psp instead.