Qurbani – Nafl Or Farz?
No need a list like we all know zakat Salah and som are frz and hujj is frz with conditions like you have enough money and health to perform hujj and that you mention above is charity which is nafal mostly people can’t do that so it’s a nafal . Qurbani is also like some can afford it easily and some cannot do it that’s Why it’s nafal
Wajib is just a fiqhi terminology. From pure Islamic perspective something is either fard or it’s a nafil. Fard ibadahs generally have parameters and exceptions defined, for example salat has timings and alternate modes defined, saum has timings and exceptions defined. zakat has timing and nisab (exception) defined, etc.