I would wear a 3 button waistcoat for black tie, otherwise a 5 button waistcoat. A 3 button waistcoat exposes the shirt front and studs. I would even push the envelope and wear a 3 button waistcoat in a fabric that did not match the jacket, though a matching vest is nice, too!

I totally understand how you feel about shoes. I am smaller, and prefer shoes that are cut closer to the foot and are not heavy; Italian shoes work well for me. I have a very good pair of English made brogues that will last forever, because they feel so heavy that I can't stand wearing them. I only wear them when I feel guilty about having such a well made pair of shoes sitting in the closet.