By not using most of main functions on iphone... just to save battery life?!
Why get the iphone in the first place then?
Get a external battery jacket, use the iphone to its limit, that's the right way to use iphone.
Push, Notification, IM, Facebook, and more... enjoy it, just enjoy it.
For those whom want to save battery life... get a cheap feature phone which could stand by a month before needs to be charged again.