Thanks for the responses. I will consult with a carpenter friend of mine that knows his stuff pretty well before doing anything. This project is way over my limited capabilities. In the end, I may have to live with what I got.
It's little things like this that make me about the building process. I've come across so many seemingly minor things in the 3 1/2 years i've lived here that I wish I would have asked the builder to do differently. Builders of middle class housing do the bare minimum on everything, unless specifically requested to do otherwise. To change things afterwards is a headache, $$, and usually over my head. I thought I had all my bases covered during the build, i'm surprised at how many things i'd do differently or requested if I had to do over again. Oh well, first house...learning experience I guess.
what sucks is the 20.5 " space between the trusses.If they are installed 24" on center,that would give you the 22.5 " opening.I would check other areas of the ceiling to find a space where the trusses were layed out correctly and put your stairs there.It's a little more work with patching your drywall on the ceiling and cutting the plywood floor out,But you won't be tempted to cut a truss.