Portrait of a Mallard (D800 Day One)

Please look in large ("L").

*Gasp* I don't know where to start; I love the D800. I'm so relieved that I could cry.

This is SOOC but for a crop; few of the pictures desperately needed tweaking.

Today I tried only the 24-70mm F2.8: I went to the pond (not ideal turf for the more wideangle zoom lens) but was blown away. My early shots were shaky (I'm used to having a VR lens) so I increased the sensitivity to ISO400 (the highest that I would previously use) and everything came out nicely.
I was torn about what to blip. I had a lovely time at the pond: there are two sets of cootlings (v. young: they were being very shy, but I got some nice shots nonetheless), one set of moorhenlings (hiding), and two sets of mallardlings (the previous brood that I blipped, and another brand new set).
I chose this mallard because I think it is subtle (it certainly isn't a popping "wow" shot) but the beauty is in the detail: the colours and water running of its head are something I've struggled to capture before, and this is all SOOC. The F2.8 is so fast, and focuses brilliantly too; I love the very narrow DOF it can achieve.

Hum, I'm still super nervous about the camera. Would anyone be able to offer advice on any of the following? I'm so careful about kit (/everything), and found my D200 with 18-200 very low-stress: I felt I could take it anyway as it had a good case, and I rarely needed to change the lens (I only changed it when a friend loaned me his macro lens a few times).
1. I've a new backpack to carry the D800, 24-70, and 70-200: they fit best if the D800 has the 24-70 mounted and sits with its LCD down and lens up. Is there any reason that this less typical orientation shouldn't be used?
2. The 70-200 is about as wide as the bag can take, and the bottom lens cap is palpable through the wall of the case. Is that too snug?
3. Our house is super-dusty and I worry about switching lenses when there is so much dust in the air. I'm quick about it, but has anyone any advice for where is best to minimise dust contamination? At the common today the air was full of pollen and blowing seed umbrellas so it seemed foolhardy to switch lenses there.