All scientific theories are models; that's generally considered true by nearly all scientists. What would a theory be if it's not a model?
That's correct. They are. As the saying goes, all models are wrong but some are useful.
> And we are just very advanced “computers.”
To a physicalist, yes, this is true.
I may be missing the context of what you mean by model and somewhat agree with your original critique of Norvig's comment. However, scientific theories are nothing but models. For example, general relativity is not gravity but is instead a model of gravity. Quantum mechanics describes quantum behavior but it is not quantum behavior. It is a model of quantum behavior.
When physicists say "is", they mean "is modeled by" or "is a model of", whether they think so or not. None of the mathematics, or physics, or what have you is the actual thing. They are nothing but models of the actual thing that have varying degrees of accuracy and precision.
The first sentence is wrong. And the second sentence is why we play the game.