And I don't know why you mention goraud shading.
It was in response to "How does hardware lighting work". I figured that since you where asking the question, you wanted to know. You don't have to do any goraud shading to do vertex lights. That's all done by the hardware.
Duh. Except the hardware can only do 8 lights, so if you want more you *will* have to do any Gouraud Shading. Manually. In software. And I know that hardware lights aren't free, but they're a hell of a lot more free than multiple render passes.
Probably not. Although I haven't done any tests to confirm it, I see no reason why multiple lights should be "more free" than multiple renders.What I'm really curious about tho', is since you know all of this already, why are you asking about it?