I actually considered dressing as Dumbledore for Halloween, but I'm afraid my chair would have spoiled the effect. Some people might take the name more seriously than you intended, however, so perhaps it's best to keep the joke a private one.

Regarding your questions: it is very difficult to assign letter grades for this sort of class--particularly when, as in this case, each student's objectives are so different--so no, I'm afraid you won't.

Unless you would like to, in which case I think you may be confident of an A.

And I am generally available to talk in the evenings after dinner. If my office door is open and the light is on, please feel free to walk in.