I've got a 150MPH with floor problems too!
Coachmen Chris - I have a 2009 150MPH which was purchased in May 2015. I have since discovered similar floor problems. I've got a couple of questions for you if you happen to visit this thread again:
(1) It looks like you did not touch the fabric underbelly of your toy hauler. Is that true.
(2) It also looks like you did not replace the floor in the bathroom or kitchen area.
I think my project will require underbelly replacement and floor replacement in the kitchen area (around the water heater) as well as the "garage" area. For now, I'm just trying to scope out how big of a project I am getting into.
My floor damage appears to be caused by roof leaks dripping down the insides of the walls.