Regarding 1), and I realise this is anecdotal... I had a binary package manager install all of X11 and Gnome 2, simply 'cause I tried to install the svn command

Regarding 1), and I realise this is anecdotal... I had a binary package manager install all of X11 and Gnome 2, simply 'cause I tried to install the svn command-line client. This was on a server-style box I only sshed into, with limited disk space and memory (128M, I think?). ... not that I could really run Gentoo on that either though.