There is nothing wrong with seeking the mercy directly from Almighty Allah, nor with seeking the intercession of Imam Ali (peace be upon him), since the matter entirely is in hand of Allah. Seeking the intercession of Imam Ali means asking Almighty Allah by the intercession of Imam Ali, so the chances of one’s wishes being answered is greater than directly asking Almighty Allah.
The subject of the vow is the correct recitation in the normal way based on the information the person possesses. If he realized that there was a mistake, then he should correct it. If he realizes that he made a mistake after some time has passed or after he has completed the recitation of the Quran, then it is not obligated to repeat the recitation correctly, although it is better to repeat those verses that were read incorrectly.