In practice Rust's type checker accepts only a _very_ small subset of correct programs. I've been in a position to write some decent sized Rust code recently and it takes a shift in your mindset to start writing decent Rust code.
Even now there are patterns I'm unsure how to model in Rust. Arena allocation is a good example because it was partly the cause of Heartbleed too. Arena allocation in rust seems to require unsafe pointers and unsafe code blocks. You can look at Rust's standard library and see this.
2. The point being that the Rust language exposes unsafe code blocks and pointers. At some point you're going to hit those blocks (if nothing else in 3rd party code) and you're back to square one: You need to trust unsafe code that it is correct. It doesn't matter if that code is a VM or unsafe code.
*edited for some legibility.