Do some imprecise matters in the marriage contract affect its validity, such as: ignorance of some contractual terms, or discrepancy between some details written in the certificate and reality, or joking about the dowry, or complaining of obsessive-compulsive disorder?

All that has been mentioned does not affect the validity of the marriage, and the wife remains under her husband's protection. What you are experiencing is pure whisperings (waswasah); you must turn away from them and not indulge in them, for they are from the traps of Satan. Engage in the remembrance of Allah and the recitation of the Quran to block the way for Satan, and know that turning away from the remembrance of Allah, heedlessness, and idleness pave the way for Satan. Allah says: (And whoever turns away from the remembrance of the Most Merciful - We will appoint for him a devil, who will be to him a companion.) Al-Zukhruf: 36.