Selam aleykum
I know little about this so I won't be much of help, but since noone else replied I thought I'd had a go.
Well what I do know is, always seek refuge with Allah subhana wa ta'ala against shaytan. There is no help accept if Allah subhana wa ta'ala wills it.
Do you know about the forgetfulness prostration? It are two extra prostrations done either right before or right after the tasleem (depending on the reason) which excuse if you made certain mistakes in prayer.
Here's a pdf that explains it in detail:
http://www.al-sunnah.com/pdf/sahw.pdf
This might not be the answer you're looking for, but this might take away some of the stress of making mistakes during prayer.
The reason scholars can endure so much more is because of their knowledge, if you want to have a faith like theirs, then seek knowledge like theirs inshaAllah. But don't be to hung up how others pray. Each person has his own life, with their own circumstances. For example, a person living in the west has it harder then a person living in Mekka and so on.
May Allah subhana wa t'ala guide you