It's been a while I was at TW, and here I see talking about me. That's a great routine, I do similar things like you. Maxi circuit, no rest between the exercises. I generally hold the planks at least 1 minute. Also, if you want to add even more intensity to your kettlebell swings, add some flips. Underspin, overspin, sidespin... it makes it so much more intense. And I do about 35 swings (1 minute).
I think people should get at least a couple of good lessons in kettlebell training, just for the basic stuff/swing. If they learn the correct swing, then everything else will follow smoothly and quickly.
We are what we repeatedly do... Excellence then is not an act, but a habit.