VZW LG G2 With Rooted JB - Want To Upgrade to KK topic

Hi All - I am still running my LG G2 with stock rooted Jelly Bean with the LG/VZW 12B software. I only wanted to root so I could get the tether app running and freeze bloat and I have been very please with my phone and never had a reason to upgrade. However, after seeing a few enhancements from KitKat, I now want to upgrade. I've had the OTA software frozen by titanium backup but recently unfroze everything and then my phone downloaded the OTA 26A update - BUT I HAVE NOT INSTALLED IT YET. However, I've been reading about a lot of issues with this so now I'm second guessing my decision.

Is there any way to keep my root from 12B -> 26A???

Should I upgrade to 24A first? I read somewhere that rooting 24A and then upgraeing to 26A keeps root.

Is there a way to downgrade back to 12B if I'm unsatisfied by the results? I just want to make sure after the upgrade that I can still use wireless tether and still have a flawless phone.

Thanks.