2. I'm surprised you can't find a book on it, but barring that, try
this: go to a building supply store and look over the various ductwork
pieces, play with them a little, see how they fit together,

Are the rectangular duct pieces supposed to actually stay together, or
is the duct tape supposed to be all that keeps them from falling apart?
The ones I saw at Home Depot wouldn't stay together.

I haven't tried mastic but that
sounds like an awful bother when the tape works fine. -- H

I have some leaks I patched with the aluminum tape where I believe the
tape is failing, so I'm not so sure it works fine.