Thanks Fezzik, definitely a great reference point! Hard to argue with most of it.
I think Denver is 1-1.5pts too high. They have an elite defense, but I don't think it is enough to make up for an "average QB" (as you put it) and a below average/unproven offensive line. I think the future lines for their games against other top teams Baltimore, Green Bay, Indy, and NE suggest the same.
Future lines also suggest the Lions and Vikings aren't 1.5pts apart.
Regarding HFA, the below analyses point to the Ravens having a superior HFA in the range of Seattle and GB. The methodologies also have Carolina, Cleveland and Philly having inferior HFA's in the 2 pt range. Love how you reflected the reduction in HFA for the 49ers at their new Levi's stadium that caters to the wine & cheese crowd!!!
grantland.com/.../bill-barnwell-best-home-field-advantages
www.boydsbets.com/home-field-advantage-in-the-nfl