which eliminate the need for cutting and the particles generated thereby? l saw a my space demonstration where a guy was building a fiberglass hood scoop by adding pinches of glass to the mold without cutting anything.

You can. In England they're called 'chopped strands'. However .

Chopped strands r generally used either as part of a spray layup process (the glass & resin r fed through a sort of spray gun) or to make a sort of 'modge; which can be used for bedding things, filling gaps & all sort of other kluges. They r not really suitable for any normal lamination technique.

It is possible that what u were looking at was epoxy resin plus colloidal silica. This essentually uses microscopic glass strands in a matrix of epoxy resin & can be cast, painted or whatever. The result is reasonably strong.

The other thing is that chopped strands r much messier (and itchier) than normal mat or cloth. I'd stick with the conventional techniques