The rubber roof will last 10 years, if you clean and treat (coat) it every 3 years or so. The biggest issue is all the holes in the rubber roof that will let water in. Roof and plumbing vents, clearance lights, antennas, the aluminum channels on both ends and both sides of the roof, anywhere there is a screw through the rubber or fiberglass. You should reseal all those spots every 3 years to help keep the leaks down.
Also, unless your trailer has corrugated aluminum siding and front and rear panels, you have bonded fiberglass. The smooth white side panels are fiberglass backed by 1/8" plywood, with Styrofoam sandwiched between that and the interior 1/8" plywood panels.