Qiraat

Imaam making a mistake in qiraat and remaining silent for more than three subhanallahs

Q: The imaan was reading Surah Sajdah. He got stuck repeatedly and paused for more then 3 subhanAllahs. Does salaah need to be repeated because he didn't make sijdah sahw? 

He got stuck like this before. He seems to be ignorant of the masla. 

He also stands with his legs far apart like a ghair muqalid. What should be done in this situation? How should he be corrected?

Reciting the first 3 verses only of Surah Faatiha in every rakaah of salaah

Q: As we know it is waajib to recite the first 3 verses of Surah Faatiha in every rakaah of salaah.

I heard a mufti say that qiraat changes the amount of verses in the Quraan. If I recite the first three verses of Surah Faatiha and combine the second and third verse and not recite further would my prayer be valid?