[gucci-on-fleek]

> 1. The whole system download is about 1 or more Gigs

A full installation is 6GB actually, but you don't have to install everything. A minimal installation is only about 50MB, and that's enough for simple documents, and then you can use the package manager to install any additional packages you need. The main problem is that transitive dependencies aren't properly tracked, so it can sometimes be annoying to figure out exactly which packages you need to install.

> 3. The choice of packages to use, and the versons to use, is all confusing, with various books and site using various packages, often further customized.

Agreed, but you can say the same about most old and successful programming languages, so TeX isn't terribly unique here.