Qadha of Witr, Sunnats and Nafl

Q: Do we have to make Qadha of Sunnah also when we make Qadha of Fardh in each of the Salaah we have missed. What is the Shariah Ruling on this?

Q: Can we make qadha of witr Salaah also?

Q: Do I need to perform Sunnat-e-muakkadah of each Salaah for Qadha-e-umri?

Q: I heard from some Ulama or some Book that, we need to pray only Fajr Sunnah Qazaa from all the sunnah mukaidaa and no need to perform any other sunnah-e-muqaidaa, kindly confirm is this correct.

Please explain me in detail why we need to perform qazaa salaah only for the Fajer Sunah and why we do not need to perform any other sunnah mukaidaa because Fajer Sunnah is also sunnate mukaidaa.