Roof Repair

How old is the roof? Any RV "rubber" roof if properly maintained should last well over 12 years. Is it just because you are seeing the white top coat coming off that you think the roof is shot? Or is it because you have lots of leaks. If it is truely shot, then a tear off and reroof is going to be your best option.

2005 trail lite and camper guy I trust says will need replacing within a year or so. He is researching roof coating since he is now a fireman not working for camper dealership anymore.

The Safe-t-plex coating is just another acrylic roof paint. It will make your roof look clean and help to shed debris. It has barely any leak prevention. Really, leaks happen at joints and seams, not through the membrane in almost all cases. You would be better served by using Eternabond tape or Dicor sealant and buying roof paint at the big box stores.
If you want a functional roof coating system, the Line-X or similar truck bed coatings will give you protection against leaks.