Ps, in an open class do I need to take a hit for non factory sails as well as a hit for a different area?
Depends on what boat you're on. The underlying principal is that you follow class rules or take the appropriate modification. Some classes don't require "factory" sails to be class legal like Hobie does. If your sails are class legal with same sail area, there's no hit. If your sails are not class legal, use MN for same sail area or ML for greater sail area.
