i feel what you quoted is correct. To me, only a brief encounter with the philosophers after Hegel, since I always feel the rest is nothing but taking one or two the categories from either Kant or Hegel and developed into a system and then try to beat the whole "mother" system. it is like a "cancer cell" if developed well enough, it would kill the whole living body(现象学，存在主义).

As to others like 克尔凯郭尔、尼采、叔本华, i took a course on 尼采 and felt really not like him. My feeling is if you like feeling, go to a philosophical poet. Not for other two.

As the function of 0 as you mentioned, first, that 0 is a natural number or not is still controversial. Secondly, 0 can be compared to Hegel's second category of Nothing. But Hegel's Nothing seems to me to be dealing with the part rather than the whole, because, obviously, the whole cannot be nothing. They are not at the same level to me.

Finally, Hegel's work is something i did more than 20 years ago. what i put out recently is rather a lot out of my own in last twenty years thinking rather than Hegel's because i know his limitation.

it is hard to be both well-versed in everybody's philosophy and also dig deep into one and become an expert in it. Browsing through them is much easier than knowing one well enough to be really useful.

just for now