Arch makes it trivially easy to poke at the source code for any particular package, which has immensely helped me learn how things work.

I'm just curious: did that matter very much to you? if so, is there some Debian process to do the same thing?

  apt-get source [package-name]

This downloads the source of the package to the current directory. To compile, first install the compilation dependencies:

  apt-get build-dep [package-name]

Then inside the source directory, the easiest way is to install debuild and then just run:

  debuild

That compiles and creates a .deb ready to install.

The New Maintainers guide[1] has a lot of information, though most is only relevant if you want to become an official Debian maintainer; for tweaking existing packages, it's not important.

[1]: http://www.debian.org/doc/manuals/maint-guide/index.en.html

I did the exact same thing. Migrated my office (6 PC and 3 servers) from Arch to Debian for the reason you give.

I don't miss Arch since I'm very happy with it at home and on my laptop.