After my orchid drops all blooms do I cut back the bloom stalk?

NO! don't do it,it's tempting but every once in awhile you can get another bloom spike from the shoot, if the shoot starts to die back cut to the nearest green growth and apply a basic orchid fertilizer, preferably a liquid form. this is not every time but its worth it to try. only cut them stem back when it has fully turned brown and died off.