1) not sure. it's horizontal now, but i don't remember changing it. It's sorta why i came here looking for an old pic in the first place-- i don't remember moving it at all, but it's somehow positioned closer to the center of the rails now. it either slid back, or someone took it upon themselves sometime in the past two and a half years and i didn't notice...

2) not stiff as in stiffer than aluminum, stiff as in "wow... i didn't realize ti was stiff."
that's my official answer, anyway. i really don't know wtf i was talking about. i'd be surprised if the stem didn't have the slightest flex when climbing fast (esp. out of saddle), but it's barely noticeable and might even just be in my head.
for everything else, though, it's fine-- with the bonus of being light as alu and compliant on rougher roads (stick that last part up there with the other official answer).