Re: Possible alternative to Reflectix?
Radiant works both ways - in or out. Reflectix as the outside layer will keep the boat cooler in a warm climate.
The strips aren't hard to install. Epoxy either plywood solid wood strips to the hull on 16" centers after light sanding and acetone cleaning. They will have to be wedged in place overnight. You should be able to do this to any areas where it is needed in one day.
The Ethafoam I use is smooth on the surface and pretty easy to clean.
I wouldn't mess with the hull/deck joint. The only way to really re-bed it properly is to remove the deck from the hull. If it doesn't leak the bolts should be fine.
Living aboard in Victoria Harbour