Trivial history, but just the same:
As far as I can tell, no QB has ever gone 8-0 at home during his rookie season. The closest was 2004 Big Ben, who went 7-0 in home games. He did not play in the team's week one victory over the Raiders because Tommy Maddox began the season as the team's starter. Roethlisberger entered in week 2 after Maddox was injured and had his first career start in week 3.
Dan Marino was 5-0 at home, but like Roethlisberger, did not start on opening day.
Andrew Luck is currently 4-1 at home.
Russell Wilson is 5-0 at home, and his 3 remaining home games are all in the division: Arizona, St. Louis, and SF. 8-0 seems solidly plausible, almost expected. If he does it, he'll be the first ever as far as I can tell.