To fix your throttle problem, you take the handguards off and trim the outside 1/8" of your plastic throttle tube, then they don't rub.
You hear the legend of breaking your hand/wrist, but I've never actually met anyone who actually met anyone who did it. I do know the wrap around guards have saved my ass tons of times. Not just from potential broken fingers, but from impacts that would have had me pull my hands back in pain, then go head first into the next tree down the trail tree.
I do ride 95% woods, 5% track though.