I know there is a huge debate over fiberglass vs. cellulose, and I
spent a lot of time thinking about it and researching it. For DIY,
cellulose is readily available. I have a somewhat "leaky" house, and
ducts up in the attic as well. I'm working on the sealing many of the
cracks and gaps at the floor, at the outlets, and so on, but I'd really
hate to have fiberglass leaking out of these gaps. And god forbid it
actually somehow got into the ductwork!
The roofing is new, there are vents, and I'm working on getting the
bath fan to exhaust out the side of the building, not into the attic.
There should be no "moisture" in the attic other than ambient humidity!