I'd like to go to Italy next year on frequent flyer miles. I've got more than enough on either US or UAL. I'd like to fly my brother and I round trip using my miles. Can anyone help with the following questions:
1. I'm in Charlotte, he's in Nebraska. Is there a way to swing both of us to Italy somehow on the same overseas flight? I'm confused as to the alliances/partnerships of both of these airlines.

2. If we do find a route and seat availability and book, what happens if we then have to cancel the trip?

Any help that anyone could provide would be much appreciated.

dingo