Are the evil thoughts that come during the reading of the Qur’an, which relate to insulting the Mus'haf and take their owner out of Islam, considered a form of waswasah (whispers/obsessive thoughts) that should be ignored, or do they carry a legal ruling, and what is the extent of their impact on the marital bond?

These are merely whispers (waswas), and they have no effect on the marriage. Do not pay attention to them. You must repel them and seek refuge in Allah from Satan. Continue with dhikr (remembrance of Allah), reading the Quran, and supplication. Your fear that such an act might emanate from you towards the Quran is a sign of profound faith and veneration for the Quran. In Sahih Muslim, it is narrated on the authority of Abu Hurayrah that the Prophet, peace and blessings be upon him, said regarding such whispers: "That is pure faith."