Hi, Wayne
Considering the performance when exporting the animations to a game engine like Unity. What will mainly affect the efficiency? The frame rate, the magnitude of the vertices movement or the number of key frames? Maybe it's not much relevant to this course, hope you don't mind.
Thanks!
I don't know that much about Unity I'm afraid.
But if I was to hazard a guess, I would say all of the things you have mentioned have an affect.
-the more data there is (animation curves)
-the more bones
-the more vertices (and if they are deforming)
-higher frame rate
That all equals more things to compute.
But maybe the Unity instructor 
jgonzalez knows more about that.