Loose fill and fiberglass batts do little to reduce infiltration. Actually if there is air movement throguh fiberglass batts, the insualton value is minimal... and all it does it act as a big air filter... and worse, a nice place for mold to grow if you get condensation inside the walls.
You need to locate and seal the air leaks first with spray foam or caulk. Actually, once a wall cavity is fairly well sealed, the insulation value of the air gap alone isn't that bad.
Pulley covers do a descent job to seal weight pockets. Good quality storm window will seal most window air leaks fiarly well. Interior storms even better... and they will make the house a LOT quieter. Double glazing where the materials and/or thickness of the glazing is different on hte prime and the storm absorbs noise even better than thermal pane windows since acoustically they have different resonance frequencies and absorb noise differently.
Starp by looking at weather stripping on entry doors and storm door. Close off and seal unused chimneys (largest source of leaks.... big time), consider using rope caulk on the windows with the worst seals as a temporary measure if you can live without those windows being operable. Finally consider having the rim joist and in your case hte crawl space sealed professionally with closed cell spray foam.... then adeuately the crawl space to prevent moisture. Even just 1-2" will air seal it and provide insualtion nearly as good as 6" batts. In the attic, if it's unvented, use closed or open cell under hte roof deck. If it's a vented attic, then remvoe whatever is in ther now, store it temporrarily in bags, spray foam 1-2" of clsoed cell (a "butter coat"), then put the loose fill and/or batts back in over that.
After reading more, I'm leaning more towards closed cell, evne if you can only afford 1-2". It acts as a 2nd water barrier if you have a roof leak too. What would you rather have, a section of the roof rotted, or major interior water damage. IF you have a significant roof leak, odds are the roof deck will be rotted anyway. Better to tear out and replace a section of roof deck, than tear out a celings, flooring, furniture and repair major water damage. The upstairs floor and joists are permenantly damaged from a roof leak the PO's had last apring that wasn't discovered for a few days because they weren't livign in the house.
As for the roof deck "overheating" because of the foam. Even a well vented attic still gets to 120F inside on a hot day. Most of the cooling effect of a roof is from convection current on the roof surface and radiant heat. Studies have shown that the differece is around 5F.
Previous home - 1968 single story Ranch/Colonial, 1200sqft - 11 windows
Current home - 1925 2 story Beaux Arts Neo-classical overlooking the Mississippi River, 3200sqft - 48 Windows