Masbooq and Laahiq

Questions related to a masbooq

Q: Kindly answer below questions related to salaah: 

1. If a muqtadi misses some rakaat, at what point should he/she leave the jamaat and stand to continue the missed rakaat? Should he/she do it after the imam completes the 1st salaam or after the second salaam? 

2. For a muqtadi who has to missed a rakaat in jamaat salaah, should he remain quiet after the last tashahud behind the imaam and wait silently for the imaam's salaam to continue the missed rakaat, or can he/she recite durood and prayers after the last tashahud? 

3. If a person misses the 4 sunnah prayer prior to Zuhr or Jumah Salaah and joins the farz prayer in jamaat, does he/she needs to offer the missed sunnah prayer afterwards or not? If yes, then what's the correct sequence of offering the missed sunnahs? Should those be offered immediately after the farz jamaat salaah or after the 2 or 4 sunnah prayers that we usually pray after Jumah or Zuhr farz salaah? 

4. If a person makes sajdah while a couple of hair strands cover half the width of his forehead, would the sajdah be valid?

Walking in front of a masbooq

Q: In a small Masjid, the Imam used a sutrah while leading the jamaat (it is a common practice in some places to do second or third jamaat if the main jamaat is missed). Is it permissible to pass in front of people who missed their rakaat with the Imam in these second/third jamaat are completing their prayers. Will they still be considered to be behind sutrah even if Imam has completed his own Prayer?

Imaam moving forward when a second person joins the jamaat

Q: I was leading salaah with one muqtadi, who was standing 1 foot behind me, when a second muqtadi joined the prayer. However, the muqtadis did not move back 1 saff, so I dragged my feet and moved 1 saff forward. However, I dragged my feet 4 times to reach my place.

1. Is the salaah valid?

2. Is it necessary for the imaam to move forward if the muqtadis don't move back?

3. Is it necessary for the muqtadis to move behind?

Remaining silent behind the Imaam

Q: I have a question regarding joining the jamaat for salah late. What is the ruling regarding the situation if I join the jamaat while it was in qiyam. And soon after my joing the jamaat (after 2-3 secs) the Imam goes into ruku. I didn't get enough time to recite surah fatiha. Will I get that rakat as I couldn't recite the Fatiha or I need to repeat it by myself after tasleem of Imam?