Method of Salaah

Q: When performing salaah sitting on the floor, and going into ruku, how far down should one go down?

Q: In a four rakaat sunnah salaah, if a person reads Surah falaq and naas in the first 2 rakaats, is it fine to read surahs before that thereafter, such as Surah wal aadiyaat and qariah?

Q: In a 4 rakaat Sunnah salaah, if in the first 2 rakaat one reads e.g. 1 page in each rakaat. Is it fine in the 3rd and 4th rakaat to read 1.5 pages? I.e more than the first two.

Q: Whilst performing a Qada prayer, one had just finished reciting "As-Salamu-Alaykum" of the first Salaam, and before one could complete "Wa Rahmatullah" (and even before the second Salaam), one's wudhu broke. Is this prayer to be repeated?

Q: Can dua be made in Sujood after having prayed the fardh Salaah?

Q: After ruku I used to say sami Allah huliman hamida (without ha in the end) and no Ayn at Allah, will this make my salah invalid?

Q: I want to know what are the faraaidh of Salaah?

Q: In ruku should the arms be kept straight or should they be bent with the elbows sticking out?

Q: What I wanted to ask you is that how can one make dua in sujood? Is it allowed for one to make dua in a speaking way in sujood or you just make dua in your heart when in sujood and the second thing is that I want to know how to make dua to Allah Ta'ala and at what time when some one has wronged you, has hurt you etc, what should I pray to just complain about that person to Allah Ta'ala?

Q:

1. Should one's heels be apart or touching whilst in sujood? Is this sunnah? If so which part of the foot should be touching each other as a lot of people are not aware of this?

2. If one recites bismillah in the 3rd or 4th rakaat of a fadh salaah after surah fatiha as though he is going to recite a surah, but then realises and doesn't proceed with the surah, would this require sajda-e-sahw?