> I would imagine that Rust would be fantastic for implementing a database or a web browser or anything else equally complexity-management and performance driven.

Yeah that's about what I'd expect considering the language's goals.

> Safety is one thing, mandatory safety means a mandatory runtime overhead with a mandatory reduction in control and power over the code which is unacceptable.

Rust has the `unsafe` escape hatch for this, unsafe blocks can do whatever the hell they want and are "unsafe function" and "unsafe pointer" types which are known to bypass Rust's safety mechanism and can only be used in unsafe blocks.