1) To the best of my understanding, this means the Quills cannot be used on Mephisto's tiles as he cannot attack his own tiles even if they're in Mephisto's attack range.
But I'd argue that, if for some weird reason you ever need to kill off a tile of your own, I guess you can activate the Quill to put a Quill marker on one of your own units.
2) There's no rotation when using the Drill.
Ah! I thought the Quills would now belong to Vegas HQ. I hadn't seen it like that.