Naseehah to the leaders of the Muslims

It is wajib (obligatory) to give naseehah to the leaders of the Muslims, since they have faults and are not protected from committing errors, but who are the leaders of the Muslims?
i) They are the Caliphs and others responsible for the affairs of the Muslims.
ii) They are religious scholars.
As for giving naseehah to the rulers of the Muslims, it includes:
i) Assisting and obeying them in the right.
ii) Reminding them if they err or forget.iii) Making Jihad with them.
Giving naseehah to the scholars includes:
i) Spreading their knowledge.
ii) Spreading their virtues.
iii) Having good opinion about them.
iv) Accepting their rulings if they give sound proofs for their decisions.
v) Giving them the benefit of the doubt, or making excuses for them if they make mistakes.
vi) Honouring and respecting them.