Ruling on saying Ameen before the imam

What should the person praying behind an imam do if he recites a verse in which there is a sajdah (prostration)?

One who comes into the mosque joining one who has stood up to complete the rak’ahs he missed

The imaam was accused of reciting Qur’aan incorrectly; what is the status of past prayers?

Which is regarded as the first row when some people pray next to the imam?

The Imam misses Fajr prayer and argues with them about money issues

Praying behind someone who works in a riba-based bank

It is makrooh for the imam to single himself out in joint supplication to the exclusion of the people praying behind him

His voice is beautiful but he recites Qunoot in Fajr every Friday; should I pray Taraweeh behind him?

If there are two who came late to the prayer can one of them be an imam and lead the other?