You can unlock the bootloader, and root stock 4.2.2
I just got my phone today, soon as it turned on it nagged me about system update and I went ahead and updated it then I shut off the phone held volume down then pressed power.
It booted into the boot loader I opened adb and typed
fastboot oem unlock. It said it will wipe your phone back to factory, basically a factory reset. use the volume up to choose yes then power to select.
then its done.
After that you want to have su zip on the phones sdcard and download the recovery of your choice have that image in your adb/fastboot folder and put the phone back into fastboot type
fastboot boot (recovery image name) your recovery opens and you can install su zip just like normal, thats it your rooted but at this point you do not have a recovery.
I used the app on playstore to permanently flash recovery.