Ebb
Sail only in warm climates and keep all of the hatches open for ventilation. Condensation should be minimal!! Being a member of the hoards that elect to continue living in the frozen food section of our country, I too will be insulating the hull. Not being so adventurous, I'm going to simply apply a 1/4"foil backed poly and cover it with standard issue 2" strips of some choice wood. You do bring up a good point about having a good continuous seal between the hull and insulation to prevent vapors from condensing. Everything I've read so far(if memory serves me correctly) just asks for a tight friction fit between two points. That would leave a gap for mold and mildew.
Is your distaste for contact cement a point in general or is there something specific that should keep us from using it? When will we get more pictures? Some of us must live vicariously through others.