Great insulation and hermetically sealed homes increases the needs for good ventilation. You can't just build a super insulated home without great ventilation. And obviously for energy efficiency you need heat exchangers between in/out air (Alternatively as a slightly cheaper and easier to retrofit option, a heat recovery in your heating system such as an exhaust air heat pump). Maintaining good humidity in any weather also isn't very difficult.

I agree subsidizing new homes doesn't seem necessary. This is simple to enforce in building codes. Defined efficiency limits for construction and building components (e.g. requiring triple glazing and 12in insulation in all walls) would be trivial to mandate and it's as reasonable in Florida as it is in Maine.