re: Shrimp boil - about how many shrimp needed per person

That is usually a good guess. Shrimp provied a lot more meat per pound than crawfish. If you are having a bunch of kids, you could probably even split that. Either way, if you have leftovers, you can always use them later.

I remember going to the beach a few years ago and getting a bout 4 pounds for @ 8 adults and 2 kids. We had leftovers.

Don't just boil all of them, BBQ some in the oven.