Thanks for the reply. I can't believe it's factory installed that way.
Anyhow, I did the same steps as you described but instead of DICOR I used SIKAFLEX 291 marine caulking, designed to provide a permanent seal under water.
From what I have been told by a local shop that repairs RV (best reputation around here), this caulking is superior to dicor on Fiberglass. It's important to mention this as Sikaflex 291 will melt the rubber roof material.
For fiberglass though, it is extremely efficient. I sealed the perimeter of the roof, as well as front and rear caps. All vents, etc., I used transparent ProFlexRV in a can. I also sealed left and right front windows with transparent ProFlex RV caulking, and did the side modlings as well.
All that needs to be done now are the rest of the windows, but with the awning over them it seems water rarely gets to them.