#1: Teach your kids whatever you'd like to teach them. I would think it's in their best interest to teach them to be accepting of others and to follow their own heart, even if they themselves or others are very different from their peers. Don't judge harshly because others are, and recognize that everyone is an individual. [note: my answer has nothing to do with homosexuality specifically]
#2: I think any business should be priviledged to offer or deny their services to anyone they'd like, so long as they are willing to accept whatever (legal) consequences come their way.