Does an OCD patient—who is plagued by repulsive thoughts of disbelief that are not intended as insult or mockery—deserve to marry, and is he considered a disbeliever because of these thoughts?

This type of waswas (whispering from Satan) is one of Satan's traps. Whoever is afflicted by it must occupy themselves with the remembrance of Allah and the recitation of the Quran, not giving Satan any room, and seeking refuge in Allah through supplication and dhikr (remembrance), requesting Islamic ruqyah (exorcism), and consulting doctors.

Ugly disbelief-related actions and thoughts that occur unintentionally are not held against a person, based on the verse: "And there is no blame upon you for that in which you have erred, but [only for] what your hearts intended," and the Prophet's (peace be upon him) saying: "Indeed, Allah has pardoned for my Ummah their mistakes, their forgetfulness, and what they are forced to do." However, if they occur by choice, then that is disbelief, but repentance is accepted. It appears from the question that you are a believer, and you are permitted to marry a Muslim woman.