The issues you mention exist in C++ without runtime compilation, so don't pose a particular blocker to using runtime compilation when you want fast iteration in C++. This is all intended for development environments, so 'destroying the world' simply means closing the application and restarting, which without RCC++ is something you have to do every time.

So there may be benefits to using Rust, but the issues you've posed are not ones I've found were my primary concerns when working on code which needs fast development iteration.