No. No we don't.
I was told not to use every single technique ever used in the entire text. There are ways to single out the better ones...
For studying a text ie film, it is important NOT to use overly popular or obviously related scenes. If markers read the same crap over and over again, 1. They have something to compare yours to, and 2. Markers don't want monotonous "safe" examples. This doesn't apply if your text is vague.
The great exam essays I've read only use 1 or 2 main examples/scences/phrases from each text. They elaborate the crap out of them in terms of technique, form, style, etc, but only on a few examples.
So the few examples you choose to represent your text with should strongly support the base of your argument in the first place.
Hope I helped. And changed your mind ;P