We had a new roof installed last fall. It now has a continuous ridge vent. The roofer said we should install more ventilation in the soffits to improve the balance and we would like to do so. The attic is about 1,000 square feet (38x26). The ridge vent goes almost all the way across. We also had them install baffles between all the joists so at least that is done. It is a typical roof with the soffits on each of the two 38' lengths. The current soffits overhang about 12 inches and about 1 of every 6 pieces covering the soffit is vented vinyl with the rest solid vinyl. We pulled back some of the vinyl soffit and low and behold it is almost all plywood underneath with an occasional rectangular metal slotted vent. The vented vinyl soffit pieces don't even line up with the slotted vents in the plywood - it looks like the siding installer just put it up in a nice pattern regardless of where the vents are. So we are planning on pulling down the existing vinyl soffits pieces, cutting away some of the plywood soffit, and then reinstalling 100% vented vinyl across the entire length. But I need help calculating how much plywood we need to cut away and do we actually need to install/reinstall metal vents only to cover them with the vented vinyl? That seems to defeat some of the purpose by adding barrier to air flow barrier. Thanks much!

The white paint on flashing was coming off by itself. It was very chalky. I scrubbed it with bleach and TSP. Now I have only aluminum. Replacing is not an option. What primers, paints and methods should be used to have a paint that lasts and looks good?