Originally Posted by Pessimeister 
I didn't know about that Bosnickel story you mention. I managed to answer all of his questions correct the first time, using both hints as provided though!
You can only get the boots if you answer ONE of his questions WRONG ! - At least that's what I've read about it. And I don't remember anymore which one (which question) it was …
Regarding the apprentice … You can of course reload the game if you don't get the desired result …
Spoiler
The "good" ending of this quest would be that the apprentice is free again.
The "middle" or "neutral" quest ending is when … all three are in ONE body …
And then there is the bad ending as well …