1. For someone that installed Linux From Scratch, I can say that it's really nice that most of softwares use that. It's maybe not standardized like POSIX or other systems, but it's some kind of standardized by default.

3. It does not download the dependencies but it can verify that your system has all it needs to build the project.

I don't have much experience with make and autotools so feel free to disagree with what I said and say why.