Nawaafil

Q: What nafl salaah can one perform during the day for rizq and sustenance and for success? What must ones intention be when performing such nafl salaah?

Q: After praying Fajr, can we offer nafl or do we have to wait after sunrise?

Q: If I join an Eshaa Salaah behind an imaam with the intention of nafl, after missing the first 2 rakaats. Will I have to make the missed rakaats after the imaam terminates the salaah? Or will the 2 rakaats of nafl be valid and I may end the salaah with the imaam?

Q: In the 4 rakaats of Salaathul Tasbeeh, must one read a surah after Surah Faatiha in all 4 rakaats or read only Surah Faatiha in the 3rd and 4th rakaats?

Q: Regarding the two nafl after the Witr Salaah, I have seen and been told that it's sunnah to read it sitting down. What if I am young and have no ailments that require me to sit down and read this salaah, is it still sunnah to sit and read it?

Q: I have a habit of making intention for Salat-ut-Tawbah, Shukr, Haajat & Tahajjud in a single two rakaat nafl salaah. Is this permissible and will it be more effective to do them individually?

Q: I want to know if one can perform two rakaats nafl salaah before Fajr salaah besides Tahajjud and the sunnah of Fajr?

Q: If a woman has qadha salaah, is she allowed to read nafl salaahs (chast/awwabeen, etc.) and is she allowed to read the sunnah salahs (sunnah of Asr, etc.) or must she first complete her qadha?

Q: A person is in the habit of reading nafl salaahs. If that person has limited time (e.g. he is running late) should he hastily read his nawaafil (though the namaaz is done) or should he leave it out?

Q: If a person commences performing four rakaats sunnat ghair muakkadah, before Asr or Esha, but due to the jamaat salaah starting, he only performs two rakaats instead of four, then will he need to perform these four rakaats later on after the jamaat? (The reason I am asking is that I have read that once we start salaah, even a nafl salaah, it becomes waajib to complete it.)