Re: Backward Roll - Risks and benefits
Great topic. I've only been training for a few years, but I haven't found them necessary for any techniques - backwards falls (half rolls) have been sufficient.
The only time I've found them "convenient" or less awkward was in line techniques, where nage throws a line of ukes one at a time. It tends to prevent me from gumming up the works if I take a full back roll out instead of doing a fall and reversing/stopping the motion.
On injuries, I haven't personally seen any serious ones from backwards rolls. However, I did slam my head on the mat doing one once a couple years ago due to uke stupidity - I anticipated the full roll when the throw was more straight down than a projection. That wasn't very exciting, and probably wouldn't have happened if I had just stuck with a simple back fall.