This is a fast ArchLinux Installation example. As you can see in 15 min. I have installed Arch + Xorg + GNOME
There also some tips about speeding up pacman using powerpill with aria2c that you can use too.
Arch Linux pulls in LOADS of dependencies for applications which really don't need what it's pulling in, why it does this, I don't know. But it's not Pacman which is at fault, it's the way the packages dependencies are listed.
a tool that updates packages from the AUR repository seperately from a normal upgrade from official repos.
Otherwise you could just use Yaourt -Syu --upgrade to upgrade ALL packages in all enabled repos
http://wiki.archlinux.org/index.php/AUR_Helpers#aurget