My xbox is flashed. I don't have any clue about how an rgh works but if it also lets you play burnt games online then I guess it works too. So no an rgh isn't required, but a lot of other stuff is. Just wait out the three days.
I enjoyed it for sure. I got to level 28 of 55 in one night, it sure is addictive
The weapons are extremely balanced from what I've seen so far and I don't think I've played on a map I absolutely hate yet. This might change since I only have 5-6 hours on the game so far but that's my first impression.