actually,
such a class could get by under certain conditions:
If the aim of the class is to demonstrate differing
software developement kits and the use of scripts ...
FPSC is great. It serves as a great level editor and would
be more suitable than a game of half-life

Also,
since most studants probably have a copy of HL, Doom, UT ....
The voilence level is really not an issue because its
"monitored" and "directed". Studants would be required to do
much more than just play a game. Also, this would serve
to bring more students into the class ... more money ...
There's modeling to learn, sound effects to create, and a story to write. This could be a fun and challanging art class. But,
how would you grade the students ? That's much harder than a simple
history test
just my 2 cents worth.
good luck convincing the parents or the board