I've seen many teams do the cheer first. I remember growing up watching OHIO always start with the cheer and I loved it! Back when I started coaching UCA teams, I played with the idea. I was advised by many whose opinions I value to not open with the cheer, so we never have. Our cheers always get perfect or close to perfect scores, so we stick with what we know works.
As for ending, we do the typical pyramid. Reason is because the UCA dances are typically 2 -8 counts and IMO thats not a great ending. In allstars you can have fun, long, high energy dances that make a statement at the end. Hard to get that out of 2 8 counts, so we do pyramid to leave our last impression.