Mistakes in Qiraat

Q: During Fajr prayer I made a mistake in Surah Dahr. Instead of و يَطُوفُ عليهم ولدان مخلدون I recited و يُطافُ عليهم ولدان مخلدون. Is my prayer valid?

Q: During Friday prayer, the imam made the following mistake during recitation: In سورة البقرة ، آية ١٣٦ ، instead of لا نفرِّق بين احد منهم , he recited لا نفرِّق بين احد من رَّبِّهم Is the prayer valid?

Q: While offering qaza of esha salaah, I made the following mistake during the recitation of aayat 15 and 16 of Surah Fajr, instead of فَيَقُولُ I recited فَيَقُولَ. Is my prayer valid?

Q: I have heard that in Surah Fatiha اَلۡحَمۡدُ has to be pronounced from the throat otherwise the meaning will be changed. I pronounced all my previous prayers without pronouncing it from my throat, are all my previous prayers invalid and do I have to repeat them?

Q: An Imaam performed Fajr Salaah, he recited Surah غاشية. In this Surah he read وجوه يومئذ غاشية instead of خاشعة. Will the Salaah have to be repeated?

The Imaam occasionally gets confused between laam and raa, should he be making Imamat?

Q: While reciting Quraan in prayer, if one recites first two verses of a surah but forgets to reicte the third verse and goes on to the fourth verse, meaning he has recited total of three verses but had omitted one verse in between by mistske, would the prayer be valid?

Q: I heard that when reading Surah Fatihah, you need to make the sound of the “dal” in “wa lad-daaalleen” longer, till 6 seconds. However, it is difficult for me to count how many seconds and often I finish it in 3 second or so. Is my prayer valid even if I do it deliberately because I can’t count seconds when reciting?

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:

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?