Is it incumbent upon the person suffering from obsessive doubts (al-waswās) who intentionally insulted the Companions and the Shaykhs, and who does not pray, to pronounce the Two Testimonies of Faith (Shahadatayn) and perform a ritual bath (ghusl) upon repentance?

Abandoning prayer and insulting the Companions are among the greatest evils and sins. Insulting the Companions is an aspersion against the religion because they are the transmitters of the religion; it is a denial of Allah and His Messenger. Abu Zur'ah al-Razi said that whoever disparages any of the Companions of the Messenger of Allah, peace and blessings be upon him, is a heretic (Zindiq), because they are our witnesses to the Qur'an and Sunnah, and slandering them is an attempt to invalidate the Book and the Sunnah.

As for intentionally abandoning prayer, it is worse than murder, adultery, theft, and drinking alcohol.

Repentance from insulting the Companions and abandoning prayer is obligatory. The repentance of one who abandoned prayer is by performing the prayer, and this is the most correct view, because his disbelief is due to his abstention from it, so his repentance is by performing it. It has also been said that it is by uttering the two testimonies of faith (Shahadatain).