Method of Salaah

Q: During salaah, due to anxiety/anger because I heard someone in my family making unnecessary loud noises, I raised my voice in recitation a little. Is my prayer valid?

Q: In a few of my past prayers, I remember I had moments where I’d get confused or make a mistake during prayer due to being nervous and in those moments I’d cough or sniffle without necessity, as a result of embarrassment and me not wanting anyone around me to think that I was struggling during salah. Do these salah’s need to be repeated?

Q: I heard in salah, errors to do with waqf dont matter. Does this apply to stopping in the middle of a word and then resuming?

I attempted reciting waladhaleen twice and every time between the ‘leen’ part, my voice stopped because of an obstruction in my throat. However, the third time I tried again and the same thing happened, after the pause, my voice came back a second later and finished reciting the remaining letters. Because I paused abruptly, is my salah fine?

Q: Is it compulsory to recite 'wajjahathu wajhiyya...' in the starting of sunnah prayer and "allahumma ighfirlee maa qadhammthu..." in the tashahhud of sunnah prayer.

Q:

1. I recited ‘saliheen’ with a bottom throat ‘ha’ and noticed during the middle of reciting it during the enlongation of the last syllable. During the elongation of ‘heen’, even after I realised, I still pronounced it with my lower throat. Is this considered intentionally reciting something wrong and did it invalidate my prayer?

2. During the du’a portion of Witr, I usually recite Rabbana Atina Fidunya 3 times. The second time I recited it, it felt like I had recited ‘Rabbana atina fidunya hasanatan wa qina adhabanar’ as opposed to the correct full invocation. Because of my uncertainty, can I assume my prayer is sound?

Q: In namaaz, after reciting the dua after durood, Rabbi inni zalamtu..., can we recite other dua's before salam? 

Q: What masnoon duas can be read after a fardh salaah?

Q: Is it acceptable to raise ones hands in dua immediately after salah?

Q: What is the correct zikr to recite after each salaah

1. 33x SubhanAllah

33x Alhumdulillah

34x Allahu Akbar

Or

33x SubhanAllah

33x Alhumdulillah

33x Allahu Akbar

1x Laailaaha illallahu wahdahu La sharikalahu lahul mulku Walahul humdu wahuwa ala Kulli shayin qadeer.

I am confused as I understand both are mentioned in the hadith. Which is the correct zikr to recite after each salaah.

Q: When performing salaah, can one recite Surahs against the sequence of the Qur'an? For example, can one recite Surah Falaq in the first rakaat and Surah Kaafiroon in the second rakaat?