why does the dad keep

I think he was just unused to having a woman in the house again. Since his wife died it seemed the Dad kind of retreated within himself a bit and lost touch and having Tracy in the house made him feel a bit alive again.

Yeah, he's just a sad and lonely guy. It was a very big deal for him to have a woman in the house, especially one that was as nurturing and sweet as Tracy. He was verklempt.

This film has a dark comedy back drop. That's part of it. Do you really not get it? The father and his brother being isolated from women in general and not knowing how to talk to women? He's repeating "superb" because he's nervous and just using the only word that's popping into his head. The son is just repeating dad.

Yea, the two characters (the father and brother) were obviously meant to be pretty introverted, awkward and anti-social, especially around women. What I don't really like is how they kind of went overboard and made them cartoonish, borderline depressing even, in order for comedic value I assume. They really lacked any scenes whatsoever showcasing any semblance of emotional depth. No wonder Willy Boy was embarrassed.

And what is the deal with David Arquette as the brother? He acts like some totally anti-social, creepy gremlin, in manner and appearance. He can't even bring himself to hug his brother, as almost everyone else does, as Willy is saying goodbye at the end. I wonder if maybe he was meant to have something like severe anxiety or possibly Asperger's and the idea was scraped in the final cut or something.