We took delivery of our 2504S Jan 2015. We have had a number of issues with the latest being a kitchen sink water leak that made a heck of a mess. Still waiting for our dealer to respond to our repair request (on-going saga).
#1 Ceiling Fan: we have never had a need to have a powered fan, and we have camped in 100+ degree whether several times. The AC is all that has been needed. I seriously doubt that Forest River put extra wiring by the vent, so I would use the power to the front light as my source.
#2 Bathtub Squeak: it is a squeaker, but we spend as little time in it as possible unless we are hooked up to city water and sewer. I like your spray foam idea. I would just want to make sure that it doesn't impede other repairs.
#3 Loose Murphy Bed: we haven't had that issue, but your post makes me want to log it it as a future issue.
#4 Bowing Tanks: this seems to be a common thread and issue that we haven't experienced...yet! There have been numerous posts on this topic covering everything from bowing to the tank falling off while driving. Our rule: don't drive with a bunch of water or sewage in the tank. I think you're just asking for trouble when you have hundreds of extra pounds hanging there plus it makes the trailer a lot heavier to pull.
#5 Forest River installs crappy stereos and speakers. It is one issue that I plan on resolving this year. I have watched several videos on replacing RV sound systems. It seems like most manufacturers go bare-bones in this regard. I will post my solution.
#6 Furrion TV: another cheapo product with limited channels. We recently stayed at the KOA in Flagstaff AZ and had to borrow a digital box that they fortunately provided to give us access to their cable channels. You are doomed if the channel numbers are in the hundreds. We don't watch much TV when we are camping, but the last trip was for 17 days and it was during the NBA finals, so I had to see my Warriors games even if they lost.
#7 Bike Rack: not bike riders (we should be), so no help here. I did look at the bumper as a possible rack mount. I wouldn't do it...too puny.
#8 Backing Up the Trailer: the trailer is incredibly easy to back up. I have not noticed your issue, but then I try to avoid sharp turns. I have trailer backup assist on my Ford F150, and I never use it.
Leveling Trailer: the best purchase I made was to get the
Andersen Camper Wheel Chock and Levelers