Tic,
It sounds like the slide seals on the bedroom slide that is leaking needs service to repair the leak, and that usually, but not always requires seal replacement and slide alignment. The draft under the sofa probably only needs the wiper under the slide replaced, and not resealing the entire slide if you have no leaks.
It is a common occurrence for a shop to replace a slide seal, and create a leak where there was not one before. Therefore, I am not in favor of the idea of replacing slide seals as a preventive maintenance item. If they leak, replace them if needed, but if they are serving you well and doing what they are designed to, save the money and leave them alone.
The material that slide seal are made of is the same type material that rubber roofs are made of on 5th wheels and many entry level class A motorhomes. This material has a life expectancy of 15 to 20 years or more with it constantly exposed to the sun. Therefore, your slide seals that are protected from the elements most of the time should last at least as long even with their flexing as the slides are put in and out.
Gerald