My votes:
Religion - I'm Jewish myself, so I'd prefer it if we weren't super religious as my knowledge of religions other than my own is minimal. That said, my opinion on this isn't a strong one. If everyone else wants to be Lutheran or something, I'm cool with it.
Political - Being that this is a white American southern family, I was thinking conservative. 
Social Class - Can we be broke? Please? 
Last Names - Something that's common in the South. Calhoun, Dale, Williams, Smith, etc. 
What Family Member are You - Depends on whose perspective. He's the mother's sister's kid. Based on the accepted characters, Linus is Robby's grandson and Forrest's cousin.