I don't think that Rust is trying to test out a programming paradigm or whatever, I'm saying that these "seemingly arbitrary rules" get us a lot of things, by proxy of a certain paradigm, and reducing it to "data race freedom" (when it's so much more) is something we should avoid.
(My comment seems to focus on the discipline, I was just using it as a proxy for all of the things it gets us)
Furthermore, I still think the best phrasing of the rules is for that guarantee: if a rule is removed one can usually construct fairly simple programs that have data races/memory unsafety. Of course, it is definitely true that the arbitrary rules have other benefits, but if there was a simpler scheme that gave the core memory safety without the other things, I think Rust would've adopted it.
Put another way: Rust isn't aiming to be top of the pack in terms of enforcing a certain programming style, where as it is aiming to be top of the pack in terms of safe systems programming. (It might happen to be the best language for the former, but that is a consequence of the latter, not the other way around.)