Not a dumb question - only reason was because I wanted an excuse to play around with css animations and see how powerful they are in their current state.

SVG would probably be much more robust as a solution (as would canvas have been) - I think the demo shows more than anything that CSS3 animations need slightly more reliable support across modern browsers before they are a viable choice for doing some really nice things with them.

I might be able to answer this. Animating SVG is tricky, groups is a particularly issues because each element inside a group has to be animated as opposed to just animating the parent group tag (which causes a lot of issues with rotations in particular, you have to break out the trigonometry in javascript).