Sajda-e-Sahw

Q: While offering zuhr prayer alone, I mistakenly started to recite surah al faatihah in the rukoo. Should I have offered Sejdah sahw?

Q: Sometimes, I lose focus during Salaah for over 10 seconds wherein I remain silent and do not recite qiraat. When this happens, I silently think about worldly matters. I don’t do this on purpose. It just happens and takes a while for me to realize that I should focus on Salaah. Does this invalidate the Salaah?

Q: I made a mistake in one of the prayers but forgot to do sajdah sahw and got up. Later I remembered and then repeated the prayer. Should I perform sajdah sahw in the repeated prayer? 

Q: If I completed my salah and forgot to do sajda sahw, how to do it after salah? After salam if I sit and recite attahiyaat and say salam on the right side and do two sajdah and say salam to both sides. Is it the correct way? 

Q: If a muqtadi performs sajda-e-sahw without turning his head to the right and saying salaam, will the salaah be valid or should he repeat it?

Q: Say I recite the whole of Surah Alaq in one rakaah of salah, after performing the sajda tilawah of the last verse and getting up, do I recite the whole of the next surah al-qadr or just the first ayah?

Q: When sajda-e-sahw is to be done, the procedure is that it will be performed in the last qa'dah, i.e. after tashahhud, one salam to right and then 2 sujood. Sometimes due to carelessness I recite part of durood after tashahhud and then realize that I have to do sajda-e-sahw then what should I do at that moment? Should I proceed to sajda-e-sahw at that moment?

Q: I missed reciting the qiraat after Surah Faatihah in one rakaat of my esha salaah and I performed sajdah-e-sahw. Is sajdah-e-sahw sufficient or do I have to repeat the salaah?

Q: If the masbooq did salam with the Imam during sajda sahw of the Imam or did salam at the end of salah with the Imam, the masbooq didn't do sajda sahw at the end, is it compulsory for him to repeat the salah after the salah time has expired and will he be sinful?

Q: If someone is praying two rakaats nafl and they get up for the third rakaat, read Surah Faatiha full and finish that third rakaat, then does sajda-e-sahw, is that valid?​