A RESNET rater that does Manual-Js could get the load numbers right, but would only rarely be the right person to spec the mechanical systems or zoning, or the optimal order in which to do upgrades to the house & HVAC.
FWIW: Nate Adams uses a rule of thumb that the blower door cfm usually needs to be under 1 cfm per square foot of conditioned space before it's possible to fully control the comfort & moisture issues in a house. That isn't set in stone, but it's the right ball park. The location of the leaks make a pretty big difference. With 4400' of house and 6585cfm/50 leakage you have a way to go before hitting that magic 1:1 ratio, but at least you're not starting at 2:1 or higher.
FWIW: Nate Adams uses a rule of thumb that the blower door cfm usually needs to be under 1 cfm per square foot of conditioned space before it's possible to fully control the comfort & moisture issues in a house. That isn't set in stone, but it's the right ball park. The location of the leaks make a pretty big difference. With 4400' of house and 6585cfm/50 leakage you have a way to go before hitting that magic 1:1 ratio, but at least you're not starting at 2:1 or higher.