You need to find a better contractor. Some things which jump out at me: R13 is not enough for walls and ceilings. 70 gallon Jacuzzi! How do you plan to heat that? Will it take any hot water from your domestic supply? Do you want that much humidity in the basement???
I hail from Newbury ( in a former life!!). I don't see how 17K btu is enough to heat 3200 sq ft. Fortunately, I now am in San Diego, where there has not been a snow storm, hurricane, tornado, tidal wave, flood, or earthquake , of significance, in recorded history! I am staying put, unless the zoomies from japan get out of control!!!!!!!!