The Unreasonable Effectiveness Of Mathematics In The Natural Sciences - A Possible Explanation @EnPassant,
I think your argument is right. As far as I can see, there is no possible alternative reality in which mathematics cannot describe the physical characteristics of the universe. Any such alternative would be unstable and beyond description. The effectiveness of mathematics in the natural sciences isn't "unreasonable". It is ineffectiveness of mathematics that would be unreasonable.
Is it true that "Chaos is chaotic beyond imagining"? I think it is though we might wish to rephrase the argument to avoid the criticism that it's only because we lack imagination. What I'd like to say is that the laws of mathematics aren't as separate from the laws of physics as some of us might imagine. To say that one apple plus one apple = two apples isn't just about numbers. It's true of apples, and also oranges, houses, words, and all other discrete objects. Apples are countable. Their masses and velocities are measurable. They don't wink in and out of existence. Their mathematical properties are as much a part of their being as their mass, their extension (i.e. occupation of space), their color, their taste, and everything else about them.
If countability, addition of velocities, and other descriptions of apples did not follow mathematical laws, then the very most basic principles of our physics, and the most fundamental descriptions of our universe, would not obtain - including the law of conservation of energy. We would not exist either since we too are countable and subject to gravity, additions of velocity, and so on. Your statement about this that "... Once you have space you have law/mathematics." seems to me to be right on target.
I think the argument that you and I (if I understand you correctly) are propounding is intuitive but it probably needs a real philosopher/mathematician/physicist beyond my limited knowledge to properly flesh it out.
Alan