It's all good. I enjoy having these discussions. Also, slow NTR day if it's only us peeps chatting. :3
Just one thing: BSS can't be a subgenre of NTR if reciprocal feelings are required for NTR to happen.

Because BSS needs the unrequited part to actually be… BSS.
So it would be its own genre, as the two would be mutually exclusive (according to your definition).
That being said, I don’t mind if games get labeled NTR or BSS. I enjoy both and consume them all the same hehe. And the "FK NTR" crowd probably won’t read either.