Is the discomfort towards a person who has been proposed to, after performing Istikhara repeatedly, and whose name appeared in a predestined context, an indication that he is not her destined partner, or should she continue with him until God wills?

If the suitor is pleasing in his religion and character, and you have performed Istikhara regarding marriage to him, then proceed with the marriage, for there is good for you in it. And if it does not come to pass, there is also good for you in that. Do not rely on feelings of comfort or the reading of another person's name, for these should not deter you from what you have sought guidance for through Istikhara.