Those things which render the Salaah invalid

Q: Is the prayer of someone who has inserted something into its rectum (to block flatulence) before doing wudhu and removed it after praying valid?

Q:

1. If I use my hand, due to losing balance, when coming up from sajdah, will this break my salaah?

2. Whilst making my niyyah for salaah, at the beginning I scratched my face and then used my one hand twice in salaah. Is this amal-e-katheer?

Q: If one swallows a few strands of coconut during salaah which was stuck in the teeth, will it invalidate the salaah?

Q: Recently, I came across a clip of someone quoting the following hadith and explaining its great virtues:

عن عبد الله بن عمرو بن العاص، قال: قال رسول الله صلى الله عليه وسلم: من قام بعشر آيات لم يكتب من الغافلين، ومن قام بمائة آية كتب من القانتين، ومن قام بألف آية كتب من المقنطرين (سنن ابي داود رقم 1398)

The same person explained further that if one is unable to recite that amount of verses from memory, he may recite them looking inside the Quran Sharif in salaah, be it in nafl or fardh salaah. His argument was the practise of Hazrat Aaisha (radhiyallaahu anha), who would appoint a person by the name of Zakwaan and he would lead her in salaah during the month of Ramadhaan, while reciting from a mushaf.

My questions are:

1. Does this hadith refers to only reciting in salaah or can refer to reciting outside the salaah?

2. Is it permissible to recite looking inside the Quran sharif while in salaah?

3. If is not permissible in the Hanafi mazhab, is there any permissibly for it in the other mazaahib? Under which circumstances will it be permissible (i.e. any difference in the maslah as far as a person who knows some portion of the Quran from memory and who doesn’t know, and any difference between a fardh and nafl salaah)?

4. If a Hanafi performs his salaah behind a person who is reciting looking inside the Quran sharif, will his salaah be valid?

Q: Is it correct that if a person does an action that is not part of Salaah. e.g. scratching the body, etc. for more than 3 tasbeeh, the Salaah is broken?

If one performs Salaah behind someone who does this... Does he have to repeat his Salaah?

Q: What is regarded as Amal-e-katheer in salaah? 

Q: Does crying during one's salaah nullify the salaah? The crying is due to thoughts of emotional hurt, one's past, etc. coming to mind.

Q: In qiyaam, if I lift up my toes or my foot from ground, does this invalidate my prayer?

Q: Does cleaning the nose with the handkerchief after pulling it out from one's pocket invalidate salaah?

Q: If while performing salaah a fibre of miswaak is swallowed. Does the salaah break?