Are you any good at soldering? If not do you know a tv repairman? To open this phone and resolder the charge/data port is easy and will solve many of your problems. I suspect that if you dismantle the phone and clean it of all the dust and sweaty skin cells you will get the proximity sensor to work. I think if it were damaged it would stop working at all. The bad battery life may be due to the fact your phone is not up to the task of running apps etc designed for faster processor and so on of the later model phones. Or, you have too much on the phone. ..games vids pics.try cleaning the memory up, declutter, get best system and see what happens.