I don't think Khawaja is suited to be #3... Not at the moment anyway. He doesn't score quickly enough often enough, and it can bog us down. He doesn't have the shots yet.
Having our veterans lower down in the order doesn't help our situation. Clarke won't move from #5, which is fine, but it limits what we can do. Hussey IS best suited to #6, but I reckon it would be great if we could put Khawaja, Marsh at #5 or #6 just to start their careers instead of just throwing them in the deep end.
As for Watson, he shouldn't open with Warner, with their 'heavy' batting style, we could be two down very quickly. I think we'll need his bowling in the future, and I believe this is a great time to put him back in the team but much lower...
I don't know, is it time to move Punter back to #3, Hussey to #4, and then Watson to #6 ?? That's probably too massive a change given our batting line-up is starting to look settled, but then again, we are still collapsing too much against bowling attacks (NZ, India) that aren't the best in the world...