Re: Insulating with open cell/closed cell foam.
You don't provide enough information to even guess at savings by insulating. You really need an energy audit to tell you pay back time.
Open cell foam will pass water through, say from a roof leak, and generally needs to be removed once wet. I would use closed cell in the attic and open cell in the floors. That way any roof leak will not leak through to the ceiling and any water dumped on the floor can go through the open cell foam to the crawl space.
Be sure you live your life, because you are a long time dead.-Scottish Proverb