Depends. Your battery life is directly tied to the ROM you flash, your settings. Apps you download and of course your usage. Every flashaholic is on a mission for more power and battery life. I can suggest ROMs, kernals, scripts and settings I've used in the past. As for your phone charging slow, check your USB cord. I've eaten through three of them and the slow charge has been the first sign. The decision to root or not is totally yours. Rooting, installing custom ROMs and learning how to do all of this takes time and patience. I'm not an expert. I just love tinkering with my phone and seeing what I can create.