Roll - Vapor Retarder Issue

I am building an addition that consumes part of an attic and need to insulate these new rooms and better insulate the remaining attic. Presently the attic appears to have blown very short glass fiber fluff (grey and is not cellulose). It has compacted a good bit and appears to be breaking down. Its 20 years old, is very friable and generates airborne dust/fibers when touched. I need a good filter mask whenever doing anything in the attic. I am thinking about DIY insulating the new partion walls with fiberglass batts and the roof joists (where they form a room ceiling) with fiberglass batts with preformed convection channel inserts to separate the batts and the roofing nails. My soffit venting was already increased and I installed ridge venting with the new roof. In the remaining attic area, I am considering DIY or contracting for blown in cellulose to blanket the existing grey glass fiber fluff and increase the thickness. My hope is to seal off the glass fluff so that it no longer gets airborne while improving the R value. Are these two strategies likely to be the most economical and successful or are there other approaches that might be better. Thanks in advance, John S.

This seems like the best forum for my question. I have a switchplate that gets a little moist on occasion during the winter. It doesn't happen too much, just on the really cold days like today. It's 5 degrees right now. Any ideas on what I can do to take care of that? Thanks for your time.