Rukoo and Qaumah

Q: In Kitaab al-Asl of Imaam Muhammad it states that according to Abu Hanifa the imaam should not say "Rabbanaa lakal hamd". But in the same book Imaam Muhammad ask Abu Hanifa whether the Imaam should recite basmalah, amin and Allaahumma rabbanaa lakal hamd silenty and Abu Hanifa says yes. Why this contradiction?

Q: I would just like to get clarity on a few aspects of Salaah (hanafi).

1. What is the correct way of performing ruku, does one say Allahu akbar first and then bend down, or does one say Allahu akbar in the motion of bending?
2. In witr Salaah, does one drop their hands and then raise it for dua Qunoot, or can one raise their hands directly from the folded position?
3. After salaah, I know it's sunnah to say Astaghfirullah thrice, is it also sunnah to say Allahu akbar once then astaghfirullah thrice?
4. Is salaah valid if in a 4 rakaats fard salaah, after surah Fatiha of the 3rd rakaah, you say just 'bis' of Tasmiyah before realising you don't read a surah now? If it is valid, what is the maximum length of Tasmiyah which may have been recited mistakenly without invalidating Salaah?

Q: I have a question with regards to method of performing salaah. If one is performing salaah, whether alone or in jamaah, should the person recite his tasbeehat in a manner that the next person can audibly hear what he is reading or should the brother read it softly so that the next brother cannot hear what the brother is reading. 

Q: Must a Hanafi fold his hands after ruku when he prays behind a imaam who does longer zikr than ''Rabbana lakal hamd'' such as;

رَبَّنا وَلَكَ الحَمْدُ حَمْداً كَثيراً طَيِّباً مُبارَكاً فيه

Rabbana wa laka l-h'amd, h'amdan kathiran tayyiban mubaarakan fih