Allah doesn't see your way of reciting surahs in salah, he just watches your heart, if you love allah and you offer salah for the sake of him then your salah is of high level whether you think this the weakest salah of your life. Practice surah al fatiha in nafl prayer,try to repeat it less, say alhamdu and then stop and then say lillahi and then stop and ...
You need to recite an extra surah other than Fathihah for prayers. But you dont need to do a long surah, why not a single verse from Ikhlaas or Naas.
We can recite verse 2:255 but not 112:1? Both are single verse but only size differs. So if you dont have time, just recite a single line of a surah and that will be enough.
The chosen position of the Hanafi school and the position of the two companions of Abu Hanifah (RA) is that the best way to perform them is with sets of 2 rakahs each set ending in Salam.
It is written in Ad-Darr Al-Mukhtar the well-known Hanafi book of fiqh:
وتُكْرَهُ الزِّيادَةُ عَلى أرْبَعٍ فِي نَفْلِ النَّهارِ، وعَلى
ثَمانٍ لَيْلًا بِتَسْلِيمَةٍ ...
Short answer: Du'a from the qur'an if regarded or intended as du'a doesn't fall under this case. And this is agreed upon among scholars.
A superficial analysis
First of all the chapter "The Prohibition Of Reciting The Quran While Bowing And Prostrating" in Sahih Muslim starts with ahadith showing that among the last things the prophet () said ...