Insulate sloped roof with dense-packed cellulose
 

I'am considering insulating my vaulted ceiling tite with
dense-packed cellulose between the fiberglass batts and underside of roof sheathing, filling the air space, close the sofit vents.Hoping to keep the roof cooler. Then blowing R 50 in the upper gable attic space keeping this area vented. Will this work?

Yes. Google "Dense pack cellulose" and "Mooney Wall". Lots of information available.

This is a vaulted ceiling with trusses,I think I will keep the soffit venting and air moving up to the ridge vents.