Is the marriage of a person with obsessive thoughts valid, and has a divorce occurred, based on the words, doubts, and obsessive thoughts that emanated from him?

The words mentioned do not constitute disbelief (kufr), nor do they necessitate repentance for uttering them; especially for someone afflicted with obsessive-compulsive disorder (waswas). Phrases that might be misunderstood, such as "Even if you brought me the Prophet, peace be upon him, I would not accept you," are not considered disbelief because they can, in fact, indicate veneration of the Prophet, peace be upon him.

As for divorce: it does not occur merely by doubt, and it only takes effect through explicit pronouncement, especially from someone afflicted with waswas. One of the best ways to treat waswas is to completely ignore it and seek refuge in Allah from the accursed Shaytan.