LG G3

Hello, I recently purchased an LG G3 and had it factory reset and all that jazz. It's worth nothing the previous owner had it rooted and was running a custom ROM. I restored the stock ROM for now and kept it rooted. Although it is rooted, I am not aware of any root-level modifications. I'm using...

Hey, so when I select an iso it turns to a landscape and then it crashes. I have already installed the bios and it work just fine. I downloaded the iso for silent hill 2 for PS2 and I have an LG G3 D850 with android 5.0.1. if you want anymore details leave a comment. Thanks

Exactly what the title says, If I root my LG G3, do I lose the Optimus UI that comes with this phone or not? And also how to root.