aliasing rm to mv does have its problems. For one thing mv doesn't support -r (as in rm -rf). Another is the trouble of when the user deletes two items of the same name. Also it enables the user to rm whole directories without using any special flags, whereas typical rm doesn't work that way.

On our system (because we had a user delete the etc dir, we decided to get rid of rm) we created a shell script that parsed the cmdline for illegal mv options, and also put each duplicate rm'd item into a unique subdir that was identifiable by a timestamp/date.