My DS2 who served a mission came back less of a arrogant snot than when he left for his mission, he was so full of himself before. Afterwards, he was an adult and a pretty good one at that. He wasn't perfect, he still acted like a snot at times, as we all do, but he didn't morph into 'Peter Priesthood' robot, that guy doesn't exist! If any member thinks they have to be a Peter Priesthood or Molly Mormon to be a 'good' Mormon, then they've really lost the point if Christ's Atonement.
I only have 1 husband, I married him at a registry office nearly 20 years ago. We had a religious ceremony 2 years later AFTER he joined the Church. Polygamy doesn't exist in the Church anymore. There are breakaway groups that do practise it, but the Official one no longer does.
I have 6 children, so far only 1 served a mission. I have 2 left at home, they both would like to serve a mission, 1 has just submitted his mission papers, he'll here in the next 2 weeks if he is to. My other child would like to serve, but she wants to see how she feels when she's finished school.