Plot hole: In the flashback, neither Dorothy and Stan nor Sophia and Salvatore own a TV yet. Still, Sophia knows exactly what shows each of the four like. It's unlikely Sophia regularly watched TV before as Dorothy believed her when she lied about thinking a TV is a waste of money.
Plot hole: Dorothy's son Michael is twenty-two years old in season three. When Sophia and Dorothy reminisce Brooklyn, NY, 1954, Dorothy asks Sophia to babysit her children, one of whom is Michael. Sophia refuses, so Dorothy says "I'll just leave them with Stan's mother." They talk about Michael screaming when Stan's mother was watching over them. If Michael was a baby in the fifties, he should be in his thirties in season three.