> But then more difficult questions arise: - Is the price of slack worth it, when the alternative is having more educated users that can do very basic command line calls ?

I'm not sure that it would be difficult to wrap that up in a web interface running on a single server that does nothing but execute those command-line calls - auth, data and everything but session would be managed by the web server.

You could perhaps even make a local GUI application that spawns ssh once and reads+writes to it, and have your 90% slack functionality done in a weekend.