Yes, you can use the Zig compiler as a C backend for Nim by setting `--cc:zig` in your Nim compiler flags, which provides better cross-compilation capabilities than traditional C compilers.
Yes, I tried it recently for easy cross-compilation. You can use basically any C/C++ compiler, even TinyCC works (in most scenarios) if you want an extremely fast edit/compile/test cycle.
You can, but zigcc is essentially Clang bundled with extra stuff to make cross compilation easy.