Dumbledore gets the map from the twins, doesn't give it back and the twins don't remember about it anymore. So, we know who'd obliviated the twins. However, we don't know the results of D's "find Tom Riddle" order... Also, the twins must've known about Harry's time travels by way of the map?

I am all for the different masks, but that when a person makes many people out of himself. Here we have Tom Riddle who is definitely was born and David Monroe who was born(*), and Q.Q. who was born, and Harry's teacher could be only one of those three (or someone else entirely), but not the three at once.

(*)I mean a boy, a baby, not the "returned from Albania" one.

Ok, my head hurts, what is going on with Quirrell?

1. Where is the real owner of Quirrell's body? I mean his personality.
2. Who is the Defense Professor? One would think Voldemort, but what is this David Monroe business then? And was the person who "returned from Albania" a real David Monroe? Or could it be just another mask of Voldemort (himself his own spy, why not?)
3. The body of QQ is destned to die. Is the time of his inhabitant also up? I doubt it.