Can I safely run command-line apps in single-user mode?

Obviously fsck is pretty safe to run in single-user mode. I'm using gtypist to learn touch typing and would like to be able to run it in single user mode so that I don't have to load the whole OS just for a command-line app.

When I first try running gtypist I got a segmentation error 11, which "means that the program accessed a memory location that was not assigned". On subsequent attempt get "HOME environment variable not set."

I thought maybe I need to use su to login in as a regular user, but my user account isn't listed in /etc/passwd. Should it be?

Is it even "safe" to run applications in single user mode? If so - would I create a new user? Create an environment variable in the root account? I don't even see HOME listed as a gtypist env variable so maybe it's not a gtypist variable at all.

On side note, just learned that rather than reboot into single user mode one can just open terminal and sudo shutdown now, after which OS X will "quietly and consistently shutdown to single-user mode." Sweet.