Reciting behind the Imaam

Q: In Zohar when reading behind the imaam, are we supposed to also read Surah Fatiha and a Surah?

Q: In Asr prayer in Jamaat, when we stood up for the second Rakat, I said Bi, I had to say Bismillahirrahmanirrahim, but then I remembered that in Jamaat, we don't have to recite behind Imam, the Qira'at of Imam is enough for us, so I stopped after just saying Bi. Was my prayer broken or is it valid? 

Q: What is the ruling regarding jahari and sirri salah behind an Imam? Does the muqtadi (follower) recite anything in both salah?

Example: The last one and two rakats of Maghrib and Esha farz respectively. Should he recite surah fatiha or should he remain silent?

Q: My question is regarding the method of jamaat namaz:

1. If someone is offering namaaz with jamaat, should he be required to recite “Surah-fatiha” and a surah after that if the imam is reciting it?

2. Now in the case of Zuhr and Asr prayers (when imam is not reciting loudly Surah fatiha and Surah) do the people have to recite it or should they simply stand quiet?

3. In the last 2 rakats of a farz namaaz, I know that surahs are not recited after surah fatiha, I just want to confirm this from you?

4. If I join the jamaat in the rukooh of the first rakaat, I don’t need to repeat the 1st rakaat (this is what I understand); now when will I recite the thana “subhanakaALLAH...” ?

Q: I would like to know if I get the Imam in Ruku in Jamat, should I read Surah Fatiha first after takbir then go to Ruku or should I go to Ruku directly?

Q: Let's suppose we are offering zuhr namaz or any other namaz as a muqtadi in the mosque behind the Imaam. In the second rakat when we get up from the first rakat do we have to say the "Tasmia"in the start of second rakat?

Q: In salaah for Hanafi's, should they recite surah Fatiha while following an Imaam in fardh salaah? 

Q: Should we read a dua when the imam reads the last verses of Surah Gashiyah?

Q: In chapter no 7 (Surah Al-Araf) verse number 204 it is stated that "When the Qur'an is read, listen to it with attention, and hold your peace: that ye may receive Mercy". So why do people when praying Fajr, Maghrib and Isha (fardh) behind the imam (first 2 rakahs), when the imam finishes reciting surah AL-Fatiha, many people recite surah fatiha, although the imam is reciting another surah. Please do clarify this.

Q:

1. Should I be silent behind the Imam in the 3rd and fourth rakah of isha and 3rd rakaat of maghrib?

2. If the muqtadi recites behind the imam in loud and quiet salah is he sinful for it? Please clarify.