1. it is makruh tanzihi. durr al mukhtar: 'if the [follower] stands on the left of the imam, [where only two pray together] it is makruh' radd al muHtar [vol.1 pg. 611] : it is obvious that the makruh is tanzihi as mentioned in hidaya etc, because of contradicting the sunnah. in kafi it is said: 'it permissible but it is reprehensible [asa'a].' that is how zayla`yi reports from MuHammad. we have talked about whether isa'ah [reprehensible] is less than makruh [disliked] or worser; we stated there that it is lesser than makruh taHrimi but worser [afHash] than makruh tanzihi. --- 2. according to Hanafis, the salah shoulb be invalid - the intial and the appended both. as such, salah of one raka`ah is invalid in any case. all four have to be prayed by ALL not just as a repetition; moreover it is not sufficient for sahw alone. [i will look up for details and review this post later for mistakes, inshaAllah.] --- 3. in this case, it is like a masjid for travelers on the road without a certain jama`ah. it is better to do with both adhan and iqamah, though iqamah should suffice. durr al-mukhtar: it is makruh to repeat a jama`ah with adhan and iqamah in a mosque in residential areas and it is not [makruh] in a roadside masjid or a masjid without a muadh'dhin or imam. radd al-muHtar (vol.1 p.595): it is makruh [taHriman] to repeat adhan and iqamah for a second jama`ah in masjids in habitats. except for those who were the rightful congregation, and did not pray first. if they [adhan iqamah] are repeated in masjid on the roadside, or that masjid where there isn't a permanent imam where people come in groups or batches [fawjan fawja] , the best way is for each group to pray with both the adhan and iqamah as mentioned by qaDi khan and similarly in durar. masjid in habitats [masjid al-maHallah] means, that which has a known imam and a certain congregation as described in durar etc, [aH: i have used the word 'habitat', though residences might also be used. because many masjids in marketplaces also have known imams and a definite assembly] ---- 4. yes. durr al mukhtar: [and it is valid..] who is standing to pray behind one who is seated and can do ruku'u and sujud. because RasulAllah Sallallahu `alayhi wa sallam prayed his last Salat whilst seated, and his followers were standing and abu bakr and would repeat the takbirs loudly. this indicates the permissibility for muadhdhins to repeat the takbir loudly (act as amplifiers) radd al muHtar, [vol.1 pg.634] : "standing behind seated", that is one who can stand and do ruku'u/sujud or the one who prays by signs. [mu'm]; according to the [majority] except muHammad. it should be noted that 'seated' is restricted to one who can do ruku'u and sujud; if one is seated and prays by signs, it is by consensus not permitted. also, this difference (seated praying by signs) is debated in supererogatory prayers, where its permissibility is agreed upon by all including tarawiH as mentioned in baHr.
asak (1) If there are only 2 people praying, they stand side by side (the Imam slightly in front). Does the Imam have to be on the left? What if he prayed on the right? (2) The Imam forgot and prayed 3 rak'ahs instead of 4. The congregation did not remind him so he did salam without Sajdah Sahw. The muqtadis told him after he ended the prayer that he had done only 3. He said, "Let's just pray one more rak'ah then". He is Hanafi. Allowed? (3) In our University Islamic Society, we have one adhan for each prayer. But, there are many jama'ahs. Does Iqamah have to repeated for each and every jama'ah? (4) Can an Imam who is sitting lead those who stand? Jazak Allah, Wassalam