Many CLI commands are working differently with and without arguments, e.g. "cat foo" (read from file) and "cat" (read from stdin), so "nullglob" is dangerous option. Just check your data instead. It is bad idea to run sed on /dev/sda, anyway.
My "bash-modules" project is wrapper around libraries. It solves common problem: how to import library (where it is located, /lib, /usr/share, /usr/lib, /etc, /usr/local, /usr/local/share, /usr/local/share, /opt/..., /home/..., etc.). Instead of path hell, you can just type ". import.sh ..." in CLI, script, or library. It also should solve problem with versions in common way (via symlinks from exact version to general name, e.g. args-1.0.2.sh -> args.sh), but I have no free time to add that.