Salaah

Q: Is there any Hadith that states why there are 2 sajdahs in Namaaz and only one ruku?

Q: I follow the Hanafi fiqh and the time for Asr salaah is at 6pm but I live in a city in which we only have one musjid and they read asr at the Shafi'ee time of 5:15pm. Is it okay for me to read asr with Jamaat according to the Shafi'ee fiqh even though I follow the Hanafi fiqh?

Q: I have a question regarding a person travelling through different time zones? How does one go about determining what Salaah to perform when if they are travelling from one time zone to another? For example a person intends to travel from New York city to India. A person travelling from New York city to India or a surrounding country will have lost a day in this journey. I am writing a more clear example related to my question, please kindly advise me.

I board the airplane after performing Esha salaah in New York city, it will travel via Dubia to India. When I arrive to Dubia/India, I will have lost a day. My questions are as follows:

1. Whilst the plane is in the air, what salaah do I perform (bear in mind that I performed my esha before boarding in New York city)?
2. How do I calculate the salaah times since the plane will be travelling over different countries and time zones?
3. Can a person perform salaah whilst they are seated in their seats even though they have ability and facility to perform it in normal position in the plane?

Any other clarification or explanation or additional information will be appreciated concerning this question.

Q: While I am travelling, I have qadha of zuhr and asr namaz. So shall I read the namaz again after travelling as full namaaz or as kasar?