For now it does, but there's an upcoming experimental alternative backend written in Rust. Furthermore, there's no reason that LLVM has to be written in C++, it was just the best choice available when LLVM got started 15 years ago. Suffice to say, there are higher priorities for the Rust project than porting LLVM. :P

Yes, but there is a research project here that replaces LLVM for codegen: https://github.com/stoklund/cretonne