So I've heard my fair share of scary stories about nitrous. But my question is if I do a 75 shot and I don't miss a shift or anything, will I eventually still blow my engine?

 

depends on a lot of things. not just a simple yes or no question.
if you use it every stop light and stop sign, then it will probally give sooner or later.
with it propperley tuned, it will last even longer.
i'm not saying that it will blow, but without a tune, and the more you use it, your chances are much higher down the road.