Re: On speed
Rust does very few runtime checks -- the majority are done at compile time, and the runtime ones are normally explicit at development time (that is, you know you will be getting a runtime check). In all cases, if you *really* care about performance you can run time checks and do most of the things you can do in C, sacrificing the safety guarantees in those areas.
I would also say that Rust has fewer undefined behaviours than C, so the Rust one can optimize to run faster than the C one. Of course, it might not, but I think the idea that C is going to be faster is not true.