Sounds like you did everything quite well. I just don't slam on the pedals that hard - I try to get a good swift push off, but I'm not THAT worried about the cars behind me. It's for sure they won't move to get out of my way to let ME through a light.

I have noticed though that when the light changes is a point when things can go wrong. For instance, if you slam the pedals too hard to get going, you can pop the chain off and be standing there like a fool holding your handle bars and not moving, with cars behind you honking. I've done THAT - and that has taught me not to slam those pedals too hard when the light changes.

All in all though, I'm never too worried about causing someone a 5-second delay in their driving. If you can't stand being slowed down occasionally, then you have no business driving a car.