Are the actions mentioned - such as jesting with the names of prophets, or mocking the intellect, or not removing slight impurities before 'Umrah, or cursing the recitation, or jesting about the Resurrection, or delaying the question about the rulings of prayer, or disliking a surah from the Qur'an, or declaring someone an unbeliever in jest, or being ignorant of how to pray over the deceased, or denying the attribute of a shin to Allah - considered disbelief, or are the doers not held accountable for them due to their ignorance or forgetfulness?

Speech that might be interpreted as disbelief should not be so interpreted as long as it can be given a good interpretation. Do not issue a fatwa (definition) that you or someone else is a disbeliever. What you mentioned is not disbelief. If you feel obsessive doubts (waswasah), distract yourself from them and pay no attention to them, for Allah does not hold one accountable for thoughts and obsessive doubts. There is no accountability for what you say to yourself without uttering it aloud. A small amount of impurity is excused according to some scholars, and if you suffer from waswasah, you may adopt the easiest opinions. You must learn the rulings of worship and refrain from speaking about religious law without knowledge, for seeking religious knowledge is an obligation upon every Muslim. We ask Allah to cure you from waswasah, and we advise you to supplicate and to consult a trustworthy psychiatrist.