G2 keeps rebooting and showing LG screen before it eventually turns on

So like 2 weeks ago, my mom's phone totally crashed and it kept showing the LG screen, black, LG screen, black etc, until it turned on 5 minutes later. I factory reset her phone hoping it would fix it, which it did for awhile but not even a week later it is having issues. Screen is not responsive, phone gets very hot with barely any use, and still crashes, and if needed to be opened the same boot scenario.

I thought maybe it was the battery but if the screen is unresponsive, maybe it is something worse? Would rooting and flashing a ROM for her be any help to save this phone? Or is this probable worse than I think?

Any advice would help.