Sometimes I wonder why people even post "answers"..... sigh.
Yes, they still count as two separate units while in transport.
Yes (BRB pg 67, left column, 2nd bullet, last sentence), and they cannot fire from inside the vehicle if the vehicle moved more than combat speed (>6") (BRB pg 66, left column, 10th paragraph)
Not from inside, but they can get out and fire. (BRB pg 67, right column, 2nd paragraph)