Good luck getting traction. The web is littered with the corpses of "comment on any website" apps. The problem is that there are too many websites and too many incompatible "comment on any website" standards for any one of them to emerge as a clear leader. P.S. You list non-tracking as a differentiating feature, but how do you silence speech you don't like without tracking users?
W3C is tackling the compatibility issue. http://www.w3.org/2014/04/annotation/ https://hypothes.is/blog/peer-review-annotation/
On the other hand, maybe that's exactly what you don't want. My personal pet peeve is comments on scientific papers, where openness of this content is not only desired, it's crucial. Your situation might be different.