Qadha of Witr, Sunnats and Nafl

Q: I had many qadha salaahs and I had made the qadha of my witr salaats before all my Isha salaats. So will it have to be repeated and if so, must I repeat just the witrs or the ishas as well?

Q: I commenced performing two rakaats of tahiyyatul masjid, and thereafter, the jamaat salaah started. I immediately made salaam to come out of the salaah. Do I make qadha of the two rakaats which I commenced and broke?

Q:

1. If we perform Esha Fard, sunnat and witr and nafl but after the time of the prayer has expired we realized that the fard was not valid, what qadha do we need to offer (from the Fard, sunnat, witr and nafl)?

2. If we perform Esha Fard, sunnat, witr and nafl and before the time has expired, we realized that the fard was not valid, what do we we need to repeat (from Fard, sunnat, witr and nafl)?

Q: If a person is offering qadha of Fajr of the same day, then should he offer the sunnat first and then the fardh, or vice versa?

Q: I have nafil and sunnat prayers to make up that I used to break in the past and are now wajib. Is it valid if I make the niyyah of "2 rakat wajib"? Or do I have to specifically make niyyah of sunnat/nafil and which daily prayer they belonged to?

Q: I have recently heard that if you start a prayer, even if that prayer is nafil or sunnat, and you break it, that prayer becomes wajib. I used to do this quite often in the past. Can I offer tawbah or must I make them up? I have no idea how much I have, so if I must make them up, how should I go about doing so? 

Q: If the fajar prayer is qaza. Do I need to pray only farz for qaza of Fajr or both Farz and Sunnah? 

Q: Is it necessary to make Qadha of Witr should you miss it?

Q: A person performed his Esha and Witr Salaah on a particular day. Later, he realized that his Esha Salaah was not valid (after the time for Esha and Witr had expired). Should he just perform the qada of Esha (since it was invalid) or should he also perform the qada of Witr (even though he performed witr correctly)?

Q: Is there qadhaa for broken Sunnah Salaah?