i think when you say cut backs, it was just the deveining process on big shrimp, big cuts. they may open more as they cook.
as for not overcooking, i find you should cook shrimp the minimum amounts of time, till hey are almost done then remove from heat and they will finish cooking.
i never fry things so i can't help you there but for sauteing
, def saute in the sauce and once they are almost pink, give them one quick stir and turn off the heat and let sit for a min or so to complete the process. you may want to cut in to a big one and make sure it's cooked through but they cook so quick it shouldn't be an issue.
if frying just toss in sauce after...i'd imagine the technique works similarly since they are just sitting in hot oil after being pulled out of the heat.
if baking, you could sauce then place in oven and maybe a little more sauce once you pull them out.
i love buffalo sauce!