Can i upgrade using itunes or can i only restore from itunes and then restore backup from the cloud?
You can only upgrade using iTunes if you want to do so before it's released next week. You don't have to do a restore. Just to a backup, then upgrade. All your stuff will still be there. After that I just set it back to backup to iCloud. It was easy peasy.
Just sold my phone with a beta build on it, does anyone know if you can go from beta to retail OTA? I know beta to GM doesn't work OTA.
If it works the way it did in the past GM will get updated OTA, just like if you had installed iOS7 OTA next week.