Celtic Heroes

So I made the switch to android from ios. The device is OK it's the xperia xa with decent enough specs but some games it lags a little on like Pubg and radiation city, ch runs smooth for the most parts when soloing but it could be a diff story In a group. So I'm thinking of rooting it to overclock the device and also I can hibernate the system apps using something like greenify (from what I've read online). Read some stuff but still unsure and dun quite understand. Has anyone here had any experience with over clocking an android or even just rooting one? I'm wondering if it's safe, if it actually boosts the devices performance (can I add more ram or change the gpu?), if it can be reverced without a trace, what the negatives are (voiding the warranty dun really matter to me), and what the positives are. Any info would be a huge help.