Jamaat Salaah and Imaamat

Q: When reading fardh salaah behind an Imam, does one have to read surah fatihah even if the Imam is reading surah fatihah?

Q: Is it permissible to correct the imaam during the qiraat in fardh salaah:

1. If the imaam makes a mistake which changes the meaning of Quraan?
2. Imaam jumps to another ayaat and realises this. So the Imaam starts at the beginning of the ayaat and still does not get it right?
3. Imaam gets stuck during recitation?

​Please explain also in respect to the 3 ayaats being read at this point and also if not?

Q: In farz namaz is it right to correct the Imam if he reads the wrong ayah?

Q: Is it permissible to read namaaz behind an imam who's garments are below his ankles?

Q: If a Hanafi follows a Shafi'ee imam whose salat is valid according to the Shafi'ee madhab but not the Hanafi mazhab (e.g. when doing masah of the head in wudu, the Imam did masah of just 3 straws of hair), will the salaat of the Hanafi follower be valid?

Q: If I perform a fard salaat on my own and someone joins in,what is the procedure? My intention was not as an Imam. I am reading silently, do I continue aloud?

Q: After fajr and asar Salah, the Imaam saheb sits facing the muqtadi. Why?

Q: What is the method of making salam behind the Imaam in jamaat?

Q: If person A prays a fard prayer and Person B prays nafl prayer behind him, will Person A obtain the reward for praying in congregation (25/27 times the reward of praying alone), even though the person he is leading is only praying nafl?

Q: If the Imaam makes sajdah sahw, what should a latecomer do if he sees the Imaam making taslim but then does sajdah sahw? Should he also make salaam and sajdah sahw, or should make sajdah sahw without Salaam?