Witr and Nawaafil

Q: Does a positive istikhaara necessarily mean that the action will be carried out? Does that mean it is decreed?

Q: I came to know by one of the dawat-o-tabligh elders that we can make intention of many different namazes (e.g: if we are praying ishraq then we can make intention of tahiyaatul wudhu, tahiyyatul masjid, salaatul hajat, salaatul taubah, etc.)

1. Is it true?

2. How many total extra niyyats can we make for a two rakat nafil?

3. Can we do the same for zohar, maghrib and isha nafl prayers?

Q: In nafl salaah, can I read Quraanic duas in sajdah?

Q: I forgot to recite a surah after reciting surah faatihah in the last rakah of witr salaah. I also forgot to recite dua qunoot in it. Will it be sufficient for me to perform sajdah sahw?

Q: Is it possible for the istikhaarah to come out wrong or bad if you give the mother’s wrong name?

Q: Which salaah is more important, Sunnat Muakkadah or Tahajjud?

Q: Regarding Shukar Salaah, I read 2 rakaat to thank Allah for all that he has given me, I'm content with all that I have, but I tend to read it 3-4 times a day. Will reading it once a day be sufficient? It's more like OCD, where as if I don't read it, I might lose what I have. So will reading it once a day be fine?

Q: Can one pray nafl salah after having prayed sunnah salah if time permits before the jamaat for the fardh salah starts?

Q: Can a waladuz zina (illegitimate child) make imamat for taraweeh salaah in Ramadhaan?

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