HMMMmmm.....
I've been hearing about the ever elusive sczhizophrenic (yea, spelling, I know) control-grabbing student pilot for years, but I have never unwittingly run into him or heard from anyone who actually has experienced such a sighting.
Have any of you? I mean REALLY seen this creature?
I believe we should continue to train for this (possible, yet unprobable) eventuality. Practice a little flight deck Kung Fu every now and then. But does this guy really need to limit himself just because this clown might become a little frightened in IMC?
Have the talk with him, strap him in, start the plane, remind him what he cannot do one more time, and fly go out and shoot approaches to minimums (or your personal limits) all day long. Remember, he asked you to go along. To me, this implies he trusts you and he'll take the risk. He knows he has no business touching your aircraft. You will be PIC and he'll just sit there. If he talks too much or gets weird, tell him to quiet down or you'll have to take him home. He'll cooperate.
Or have you finally uncovered proof that "First Officer Wackadoo" really does exist?
Have Fun. Maybe it'll help to promote a little future confidence in this pilot to watch someone else doing the things that scare the hell out of him.
I know I would. But that's just me.