Witr and Nawaafil

Q: Could you please inform me about the minimum rakaats of Tahajjud namaz and can I perform it about 20 minutes before fajr azaan? 

Q: Can I perform one rakaat witr or is it compulsory to read three rakaats witr?

Q: Can we perfrom Tahajjud Salaah without sleeping because I am awake the whole night till fajar? 

Q:

1. Is it compulsory to pray sunnat-e-muakkadah namaaz immediately after finishing the farz namaz?

2. Can I pray farz namaz with jamat in the masjid and then go home and pray the sunnat-e-muakkadah namaz?

Q: I have a lot of gas when I wake up in the morning for fajr. It is almost an everyday thing. Sometimes the feeling for breaking wind is strong and I pray the fardh prayer first then the sunnah 2 rakahs in case I miss the prayer if I have to break my wudu. Is that valid given my situation of having lots of gas in stomach?

Q: Does one have to make qadhaa of sunnah salaah?

For example, if a person misses the sunnah salaah for Zuhr, and performs 'Asr, should he perform the qadhaa of Zuhr sunnats?

Q: I made istikhara (2 prayers after ishaa and dua) but I got no response. I made it many times before but got no response.

My question is, can I make istikhara dua before I go to sleep? Can I pray 2 rakats istikhara after ishaa and then make the istikhara dua just before I go to sleep? 

Q: Is it permissible to perform two rakaats nafl salaah as sukr to Allah for all His bounties?

Q: I would like to enquire whether reading 20 rakaats of taraweeh is sunnah... I have recently heard someone say that Nabi صلا الله عليه وسلم read 8 rakaats in the musjid and 12 rakaats at home. Is this true?

Also, this person has said that the number of rakaats of taraweeh was not fixed and at one time in Makkah 30 rakaats were read. Could Mufti Saheb please clarify and include some ahaadith that I could use as proof.

Q:

1. What is the method of performing Salaat-ut-Tasbeeh?

2. What is the virtue of Salaat-ut-Tasbeeh