Don’t ever feel bad about kicking performers/parents of performers/staff members/ out of your seat, they know the deal. Just be polite and say that is your seat and they’ll move. You paid good money for that seat especially if it’s in the friends section. 🙂
Also I don’t know what seats ushers are keeping nonticketed members out, maybe the 200 section but I never see ushers checking tickets in the 100s.