1. His bio signs were off because the Librarian had just flipped on a bunch of dormant DNA for him to fight the Didac with. With out it, he would have been blown away pretty early on. My understanding of this was, this was something that was hidden in humanity, just not turned on yet.
2. Looks human to me. As pale as his skin would be being in a suit all the time, its hard to make out what it would look like.
3. He has a bridge, it's clearly visable.