Could anyone tell me if there is any way how to full wipe (not just factory reset) SGN? Thanks a lot for your answers.
Boot into recovery mode & wipe from there.
If you are rooted, you can boot into CWM & do a wipe from there.
I have not found anything like simple .zip file to flash in CWM and have "full wiped" system, data and cache partitions. It looks like there is still no good time for such mods since SGN is still pretty new device.