Mistakes in the prayer
Question

 
I used not to pray, but I have repented and started to pray again, praise be to Allah. But the problem now is that I forget and make a lot of mistakes in my prayer.
I will mention some of the mistakes, and please tell me whether my prayer in this case is valid or not?
For example, if I recite Soorat al-Faatihah, then after it I recite a word, or two or three letters, of a soorah after al-Faatihah, but then I stop and start to recite a different soorah, is that permissible?
Also, is it permissible for me to pray reciting the same soorah in every prayer?
Sometimes, after coming up from prostration and standing up to perform the second rak‘ah, I find myself raising the hands with the takbeer by mistake, but I stop it and put my hands on my chest straightaway. Is my prayer valid in this case?
Sometimes when rising from bowing, I raise my hands because I forget, and I find myself letting them fall by my sides instead of putting them on my chest, then when I realize I put them back on my chest to correct the mistake. Is this permissible?
Is it permissible either when sitting between the two prostrations or when sitting to recite the first or second tashahhud, to sit with both feet upright and sitting on them (sometimes I put them together and sometimes I separate them a little, and I do same thing when I am prostrating)?
Sometimes when reciting during the prayer, I forget a letter; for example I say “At-Tahiyyaatu Lillahi as-salawaatu al-tayyibaat (All compliments, prayers, pure words are due to Allah)” – if you notice I do not say “wa as-salawaatu wa at-tayyibaat (All compliments [and] prayers and pure words).” Similarly in as-salaat al-Ibraaheemiyyah [durood] sometimes I say: “Allaahumma salli ‘ala Muhammad wa ‘ala aali Muhammad kama salayta ‘ala aali Ibraaheem, wa baarik ‘ala Muhammad wa ‘ala aali Muhammad kama baarakta ‘ala aali Ibraaheem, innaka hameedun majeed (O Allaah, send prayers upon Muhammad and the family of Muhammad, and send blessings upon Muhammad and the family of Muhammad, as You sent prayers and blessings upon Ibraaheem and the family of Ibraaheem; You are indeed Worthy of Praise, Full of Glory).”, and sometimes I forget a phrase from it. Is that acceptable?
If I make a mistake in recitation of a soorah, but then I repeat it in the correct manner, is that acceptable and can I apply that to everything I recite during the prayer? Is that permissible?
Is it permissible to look at something other than the precise spot of prostration?
Also, with regard to what is worn during the prayer, I wear a garment that has buttons and is open at the neck and a little at the chest, and I wear over it a large head covering that covers my chest and neck, but when I bow or prostrate, they both show if looking from behind and below; is that permissible?
If my prayer is wrong, does this mean that my fasting is also invalid?
I'm sorry for such a long message. May Allah reward you with good.
Praise be to Allah.~1~ 
It is preferable to complete the soorah that you have started, but if you move to another soorah before completing the first one, there is nothing wrong with that and your prayer is valid. 
~2~ 
Raising the hands during the prayer is one of the Sunnahs of the prayer. So if you raise your hands, it is Sunnah and is not a mistake, as you thought. But if you do not raise them, that does not affect your prayer. The same applies to putting them on the chest after rising from bowing. Please see the answer to question no. 3267 for information on the points when the hands should be raised. 
~3~ 
With regard to the manner of sitting, please see the answer to question no. 103886. For a description of the prayer of the Prophet (blessings and peace of Allah be upon him), please see question no. 13340. 
~4~ 
As-salaah al-Ibraaheemiyyah [durood] is Sunnah, so if you omit a letter or two, you do not have to do anything and your prayer is still valid, in sha Allah. 
~5~ 
If the mistake occurs in al-Faatihah, then it must be corrected, because al-Faatihah is a pillar or essential part of the prayer, without which the prayer is not valid. But if the mistake is other than in the recitation of al-Faatihah, it must also be corrected, but it does not invalidate the prayer, even if you do not correct your recitation whilst you are praying. Similarly, there is no blame on you if you move from one soorah to another, even though it is preferable to complete the soorah which you started. And there is nothing wrong with you repeating the same soorah after al-Faatihah in every rak‘ah, or in every prayer, if that is easier for you or if you have memorized it better than others. 
~6~ 
The Sunnah in prayer is for the worshipper to look at the spot of prostration. Please see the answer to question no. 25848. And it is makrooh (disliked) to look around whilst praying. 
~7~ 
If your prayer is invalidated in some way, that does not necessarily mean that your fasting is invalid, because there is no connection between the two. 
~8~ 
It is obligatory to cover the ‘awrah whilst praying. If a woman prays with her ‘awrah uncovered, her prayer is not valid. The woman’s whole body is ‘awrah during prayer, apart from the face and the hands, so she must cover all of her body. For more information, please see the answer to question no. 126265 
~9~ 
If the nature of the garment you wear is such that every time you bow or prostrate any part of your body becomes uncovered (the neck, chest or anything else), then prayers offered when wearing it are invalid, because of what is mentioned above about it being obligatory to cover the ‘awrah 
An-Nawawi (may Allah have mercy on him) said: If a person prays in a chemise with a wide opening in front and his ‘awrah can be seen from above when bowing or prostrating or at other points in the prayer, his prayer is not valid and he should fasten that opening, or tie something around his middle, or put something over the opening that fastens on his shoulders, or the like…
End quote from Rawdat at-Taalibeen (1/284) 
But if the uncovering is accidental, such as if the garment rides up without him intending it to, and some part of the ‘awrah becomes uncovered, then what the worshipper must do is hasten to cover up whatever of his ‘awrah has become uncovered as soon as he realizes that that has happened. His prayer is not invalidated by that, and he does not have to repeat it. 
With regard to the prayers that you offered before that in which there were some mistakes, there is no blame on you for whatever you did when you were unaware of the rulings, and you do not have to make up any of them. Rather you have to try hard to learn and find out what is correct from the Sunnah from now on, but without getting carried away by insistent thoughts or becoming paranoid, so that the Shaytaan will not spoil your worship. 
And Allah knows best.