Many people want your selvages. Save them.
The other long strips...it's your call.
I have a a bag of what I call "strips" (narrower than 1.5"). I am undecided if I like the look of most strip quilts enough to use them. I think I do...as I do like some of them--but do I want to spend my time making something like this? Good question. I think so...but in the meantime, I have 10+ other projects lined up. I live in a state of quandary about this.