Do the thoughts that come to mind—including the belief in disbelief due to the whispers of Satan and the attempt to appease him by increasing acts of worship, or preferring worldly matters over worship, or obeying a shaykh over obeying Allah—necessitate disbelief? And what is the required action in such a case?

Worrying thoughts are a serious disease that corrupts one's religious practice and worldly life. The only cure for them is to ignore them, not to dwell on them, to push them away, and not to care about them. They are a trick from Satan to deter one from worship and to spoil one's life. They do not affect the soundness of faith as long as they are disliked and shunned. In fact, the servant is rewarded for struggling against them and pushing them away. There is nothing in what was mentioned that necessitates disbelief or is considered a sin. Glorifying Allah by any number is permissible, and refraining from reciting the Qur'an and sitting with family is not a sin. A person does not exit Islam except by committing one of its nullifiers. It is advisable to seek medical treatment and consult trustworthy doctors.