An amoeba acts on its environment where a rock behaves according to extrernal force.

The rock acts on its environment as well. For example, it could hold up other rocks. Once the rock falls, it can dislodge more rocks, or strike sparks. If it falls into a river or a stream, the rock could alter its course... etc., etc. Living organisms can affect their environments in different ways, but I see this as a difference in degree, not in kind.

Life also has the characteristic of reproduction which is not how processes like combustion or fusion begin or continue.

Why is this important ? All kinds of physical processes proceed in different ways; for example, combustion can release a massive amount of heat in a short period of time, whereas life cannot. So what ?

...as making something that is alive vs a dead machine - a conscious robot not a car.

Are we talking about life, or consciousness ? Trees are alive, but they are not conscious. Of course, I personally believe that consciousness is just another physical process, so maybe it doesn't matter.

My position is that physics and chemistry, eg, do not study a driving component of reality - that which drives life.

Technically they do not, biology does that (by building upon the discoveries of physics and chemistry), but I'm not sure why you think this is important.

then what drives the level of complexity to increase ?

I don't think that complexity of living organisms always increases.

Is there a thread or some place where your position on life is expounded upon?

Well, you could start with those parts of the Sequences that deal with Reductionism . I don't agree with everything in the Sequences, but that still seems like a good start.