Attic Insulation

I have a truss roof (2x4's) with blown in insulation in my attic. As I understand it, it should be a minimum of 8 inches and should NOT be compressed. The previous owner at this house put in some 1.2 inch plywood down the center line of the house on bottoms the 2x4 of the roof trusses, effectively compressing the insulation down to 4 inches in a 6 foot wide stretch running the length of my house. I recently took up one side, ran 2x4's perpendicular to the trusses and filled the insulation back to the top, then I put the plywood back on (increasing the depth back to approx 8 inches). Now before i go ahead and to the rest of it, is this a good idea? I know this is adding a lot of weight up there, but we really can use the storage area, and of course I like being able to have easy access to inspect the roof, etc through the attaic.

Whenever messing with trusses, it is always a good idea to talk to the manufacturer - often it is stamped on the truss somewhere. Depending on where you live, the design load may include a big margin. The manufacturer can give you an idea of the best way to do this, if possible, and not compromise the system. If you ever have a house built, you can have them design the trusses to accomodate a floor so you can have room for storage, etc., or even use it as living space.