You probably just have a bent main rotor. You could also have out-of-balance blades or flybar. Your 4-in-1 would not cause a wobbly main rotor. Remove the blades and carefully run the main rotor while holding on to the landing gear (watch your hands). It is fairly easy to see if the rotor is bent this way. The shaft and gear are cheap (around $5.00). The reason you want to cut power as soon as possible when crashed is that you will be putting way too much stress on the electronics in the ESC (and could also be putting way too much current through the brushes on your motor(s)). A 4-in-1 failure due to a stalled motor would probalby result in total loss of rotor power (tail or main).

I have had my Blade for about a month now and love it! I have replaced the main shaft once (among other things) for the same reason (wobbly blades).

Steve