2.5 BB preflop raise should be enough after the first couple of blind levels, I think. Actually Ive just watched a video of a guy who is a professional tourney player and has just came 4th on a sunday million and his raises are sometimes as low as 2.2 BB, it should be enough, of course it depends on the opponents a lot.
But I agree that many of these raises from beginners mean "I can still fold if they push back on me".
However, like on 200/400, 1000 is mostly enough, I think. Even with ante. Well, as I said, depends on opponents. However, you should give yourself a raisesizing-"range". Harrington suggests somewhere between 2 and 5 BBs (2 and 5 only on rare occasions), he thinks variating raise sizes can be a good way of balancing. I dunno, I mostly raise the same amount throughout a blind level, if it seems to work.