Maybe you can ask your fiance to deal with his mother. I know when we were planning and I needed to communicate with my mother-in-law, I got my husband to talk to her because he knows her best and I wouldn't risk offending her. She'd never get mad at her own son! As for the friend bringing a guest, maybe your friend can just invite a vacation buddy who will not be attending your wedding festivities so you wouldn't have to pay for the extra meal. Just let her know you are on a budget and you won't want a stranger in your wedding photos. If she is a good friend, she will understand that you are compromising. Good luck!