Warhammer 40k: Dark Heresy. A few questions

[Enguhl]

So I just picked this up last weekend, and have been reading through the rules and testing some of the mechanics with friends, and I must say; I like it.
For anyone that knows the rules a bit better than I do, I have a few questions.

1) When using pistols in melee, does it count as point blank? Or is there something that counteracts that since its in melee?
2) Are wounds/critical wounds specific to parts, or just total?
3) Vehicles. Where are the rules for them? Are they in the core book or something else?
4) Does armor require proficiency?

Thanks in advance to anyone that answers. Possibly more coming.

[Myshlaevsky]

1) No.
2) In total.
3) Online - but they went down with Black Industries. This is them.
4) No.