You'll be pleased to know that it is irrelevant whether it was Gen1 or Gen2, because it will become whatever Gen you flash it with.
I tried everything and failed so I tried method 5. It flashes but after it completes the flash it remains on the blank screen and does not reboot. I manually then reboot it and the phone boots straight to FTM. The phone was dead before hand so I am unable to say if it is gen1 or gen2 It is the orange san francisco and I think it may be GEN 1. I flashed the gen one (europe rom) on to it using the ZTE flasher. Also in the flasher I am unable to check restoreNV either it is blocked out.
Also I cannot find the strings for the IMEI on the channel1 file using HXD, it simply isn't there :S.
Have you logged into the flasher program as administrator? If not then that would explain why the restore NV buttons are greyed out. Your phone won't boot into anything except FTM mode until you correctly restore NV memory with a valid IMEI.
Try completely uninstalling All ZTE drivers, reinstalling them and trying again. Try using a different computer. The phone not rebooting properly sounds like it might be a driver problem.
There are no strings for the IMEI - just a number, encoded as described. you have to edit the file at the offset - have a look at burstlams thread that I linked to for screenshots on how to do the editing.