Method of Salaah

Q: In Ruku', instead of reading سبحان ربي العظيم, I read سبحان ربي الأعلى. Do I nees to make Qadha of the Salaah?

Q: Recently I learned to read the Quran and learned that a lot of the surahs I recite during salah (including Fatiha), I had been misprouncing. It was small mistakes like pronouncing س in places where there should be ص or ث. Was my salah valid even with these mistakes?

Q: 

1. If an Imaam recited an aayah of Surah Naba incorrectly in the fardh of Esha i.e. instead of reciting لاَ يَتَكَلَّمُونَ إلّٰا مَنْ أَذِنَ لَهُ الرَّحْمٰنُ, he recited لاَ يَتَكَلَّمُونَ مَنْ أَذِنَ لَهُ الرَّحْمٰنُ, will the salaah break?

2. If the salaah breaks, then if among the muqtadis there was a person who was a musaafir, should the musaafir muqtadi repeat four rakaats or two rakaats?

3. If the mistake was in Esha salaah and the Esha has to be repeated, then will a person who has performed witr after the esha salaah have to repeat the witr salaah as well? 

Q: Is it permissible to recite Surah Fatiha at the time of tashahhud if you don’t know what to say.

Q: I would like to know if I get the Imam in Ruku in Jamat, should I read Surah Fatiha first after takbir then go to Ruku or should I go to Ruku directly?

Q: If Surah Ikhlaas is mistakenly recited in the first Rakaat, what is the best Surah to then recite in the second Rakaat?

Q: In one musjid, the Imam Saheb read in the first rakaat of Fajr Salaah from the middle of Surah Tahreem,

يا أيها الذين آمنوا قوا أنفسكم و اهليكم

till the end of the Surah. Then in the second rakaat he read a different surah. Is there any reason for doing so? Would it not be better to start at the beginning of the Surah, read 2 pages, then in the second rakaat finish off the Surah?

Q: In fardh Salaat, is it appropriate to recite Ayatul Kursi in the first rakaat, and a Surah shorter than Ayatul Kursi in the second rakaat? For example, reciting Ayatul Kursi in the first rakaat, and either Surah Asr or Surah Ikhlaas in the second rakaat.

Q: If I am reading 4 rakaats Sunnah salaah and I read surah Naas in the first rakaat, what must be read in the remaining 3 rakaat?

Q: What is the correct way of tasleem in namaz. What I know is, at the end of salah, should I start saying salam (assalamu alaikum wa rahmatullah) when my head is towards the qibla and continue saying salam while I turn my head towards the right and complete saying salam after I complete turning my head. This completes the first salam. Should I turn my head towards the qibla then I should start saying salam when my head is towards the qibla and continue saying salam while I turn my head towards the left and completes saying salam after I complete turning my head. This completes the second salam.

I have observed the following three cases in case of three imams who are leading prayers. Could you please clarify if the salah is valid in these cases.

1. At the end of salah,the imam turns his head towards the right and after completely turning he says salam. Then he turns his head to the left after completely turning he says second salam. Is salah valid in this case? Why I am asking this question is , I have read somewhere (I guess it is from a shia person) that if you turn your head during salah your salah will become invalid. In this case the imam first turned his head to the right, by the time he starts saying the salam his salah has already become invalid.

2. The imam completes the first salam properly as per my understanding. But he starts saying the second salam when his head is turned towards the right and continue saying the salam while he turns his head towards the left and completes saying the salam after he completes turning his head towards the left. Is salah valid in this case?

3. At the end of salah, the imam completes saying salam when his head is towards the qibla then he turns his head towards the right. Then he turns his head towards the qibla and completes saying salam when his head is towards the qibla then he turns his head towards the left. Is salah valid in this case?