[gowld]

Causality is separate. Laws of physics (conservation/symmetry) are constraints, not causality.

"a+b=7" implies that "a=3 implies b=4", and "b=4 implies a=3", without regard to what causes the other, or what caused the law to be true.

[goatlover]

By implies, I mean that the laws of physics are approximating the actual laws of nature, which would be causal.

[jhanschoo]

You are postulating here a priori that causality governs the movement of the universe. That is a philosophical position on how to interpret physical observation, but whereas archetypal temporal cause-and-effect phenomena is frequently observed, there are yet many physical phenomena that you and I regard as fact don't have obviously observed temporal causes. For example, we observe the Big Bang as well as the accelerating expansion of the universe, but don't have good explanations for their temporal cause. And everything in the universe is temporally caused by the Big Bang...

So what I'm trying to say here is that your claim here that causality governs the actual laws of nature is suspect, both because your comment has not been elaborate enough to specify what you mean by causality, and because one of the most popular notions of causality, i.e. temporal causality, seems, to a first approximation, not be a good model of the observable physics: it postulates a temporal cause for the big bang, but no time prior to the big bang is observable.