Oh, I've been a Trekkie since I was 2, and I know all sci-fi has it's screw-ups, but Doctor Who seems to go out of it's way to abuse science.
And on ST science screw-ups, I never saw the VOY episode with the crack in the event horizon, but I've heard of it, and that had me gritting my teeth for about a quarter hour. As for warp drives and transporters, there are actually laws of physics allowing those. About transporters, I'd recommend the book "Teleportation: The Impossible Leap". It was written by a physicist, and he knows what he's talking about.
Never saw "V", but from what you said, that's just dumb what the aliens did. Why not just take it from the comets, or the moons of some gas giants, instead of taking it from here?