Salaah

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

Q: During tashahhud one says "..as salaamu alayka wa alaa ibaadillaah'is salihin.." instead of "..as salaamu alayna wa alaa ibaadillaah'is salihin..". Does this break salaah if left uncorrected?

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: When praying at home where you are certain that there is no najaasat on the floor, will it be ok to pray directly on the floor? Or is it still better to use a prayer rug?

Q: Can a person pray salaah while wearing their glasses?

Q: Is qaza namaz acceptable if the prayer was skipped on purpose due to laziness?

Q: If one clears their throat in salah due to excess phelgm, does wudu break? Heavenly ornaments says one can clear their throat if compelled to do so.

Q: About 2 months ago when I prayed Dhuhr in school, one girl changed the direction of the prayer and I prayed with her even though iI had severe doubts about if it was the right direction. I then found out that it wasn't the right direction but I didn't repeat the prayer. Should I redo the prayer? And is it as if I didn't pray? I had forgotten about this incident, it recently came to my mind, what should I do?

Q: The is a hadith which states the recitation of ayatul kursi after every fardh salah. I want to know does it mean immediatly after fardh or after sunnat?

Q: I would like to know if the salaah of a female is accepted if her ankle becomes exposed (because of the knee bending) while in jalsa position although the pants or aabyah is long enough when standing?