What are the positives and negatives of rooting my Android phone?

I have a Moto G, and its always low on RAM, so I was reading about an app that changes the way the system uses RAM so you have more available for apps. I'm assuming that lack of RAM is one of the reasons my apps crash sometimes. Ex: if I run the SIRIUS radio app and chrome and Google maps or waze at the same time, the maps sometimes just stop working. The SIRIUS app crashes or stops too, but its due to crappy coding IMO, something to do with the way it sees net access and such. Anyway, I'd like to be able to keep certain apps from running in the background too, like Google plus, or other built in but ultimatly useless to me apps, which I can't uninstall.