Rust intercepts most stack overflows and aborts the program when they occur. There are some more difficult cases where legit stack overflows are still possible, the resolution to which is blocked on LLVM support on most platforms (notably, Windows is the best here).

Well ultimately any useful program will use a library that uses unsafe. All I/O is unsafe at the bare metal so while you can safely wrap it it still is unsafe internallly.

When talking about the usage of unsafe code in rust, we generally ignore encapsulated unsafe code in libstd since it has the same safety guarantees as tgr compiler itself. all unsafe code encapsulated in a safe API has these guarantees, but you trust libstd more :)