Rust is indeed a very fascinating language! I think it's indeed the best choice for getting used to low level stuff. It won't be easier to learn C(++) first.
Its ownership/borrow system and excellent type system indeed help prevent a lot of errors, even in multiple threads.
It's also really fast because costly things that are everywhere in other languages are explicit (like heap allocation, reference counting or dynamic dispatch).
It is already a powerful and very usable language, although I occasionally run into things that would be very useful, but that aren't in the stable version yet.
The only thing is that while it has a fairly big and extremely eager following (your 4th point), it'll take more time for it to compete with C++ in that area.
Then to actually answer your question, there are three things:
It's going to take a lot of time until you can write good Rust code. There's a lot to learn, about type systems, low level languages and then Rust-specific stuff. But it'll be worth it. You could write C++ code a bit faster, but it'll probably be dangerously unsafe.
Learning Rust if you know C++ will certainly be easier, but learning C++ and then Rust will be much harder than just learning the new concepts while you learn Rust.