Rust also has issues using anything besides cargo.
D also has its own build system but it's not the only option. Meson officially supports building D sources. You could also easily integrate D with SCons, though there's no official support.
You don't. Any D compiler is a C compiler too, so it can take C headers without bindings or any overhead added.
Hint, before keeping to discuss what D can and cannot do, better go look how long I have been around on D forums, or existing projects on my Github.
Anything that has stable ABI does.
> go look how long I have been around on D forums
You claimed higher up in this thread that D requires bindings to interoperate with C API. You don't seem that well informed really.
D also has its own build system but it's not the only option. Meson officially supports building D sources. You could also easily integrate D with SCons, though there's no official support.