Been using smart phones since the original Galaxy and owned each of the LG G series since the G2. I've never used a screen protector and never had a scratch. I do use an otterbox commuter though because I'm somewhat prone to dropping things.
I've been seeing both charging issues and battery drainage since upgrading. Looking at my battery usage, it shows "Phone Idle" as the highest one, which is odd since it's usually screen. Phone idle is using 13% while screen is using only 8%.