1) Mostly no, the hairs retreat into the body, but there is also some shedding. This is my not very firm belief and I will not die on that hill, but I might build a trench halfway maybe.

2) No, they use the teeth to puncture the vessels, then drink the blood normally, the way you would normally drink blood. I would not die on this hill either, perhaps set up a machine gun nest, in case the trench proved insufficient.