You can try to advise the client and find a resolution, but you definitely have to respect the clients wishes. I mean, if they're well off financially, but only want to invest in risk free assets despite you saying they can afford to take risk, are you really going to do otherwise if they object?
I do remember seeing that, but I'm still a bit skeptical of Schweser here. I mean, it all comes down to whether the client will accept your advice. If they do agree to accept more once you've explained the situation, it would be average tolerance rather than below average. Unfortunately this is just another example of the overwhelming ambiguity of the potential answers. I would pick low tolerance if this came up, and hope that it gave you a few sentences to justify your reasoning.
not even then. If he doesn`t want to take risk you can`t make him can you!! Ability high, willingness low, risk tolerance = low. Can you find a spot in the CFAI which says otherwise.