Does the worshipper sin if he does not correct the Imam when he omits a verse other than the Fatihah, or changes a word in a way that does not alter the meaning or alters it, out of fear of distracting the congregants, especially if most of them are common folk who might dislike the Imam despite his melodious voice and masterful recitation?

Opening up to the Imam becomes obligatory if he makes a clear grammatical error (lahn jali) in Surah Al-Fatihah, or an error that alters the meaning in other surahs. It is commendable if the error does not alter the meaning. Omitting an obligatory opening up is forbidden, while omitting a commendable opening up is not sinful. The remedy for disturbing the congregants is to teach them the rulings of the Sharia and to present them with evidence from the Sharia. The fear of the Imam's displeasure if one opens up to him is unfounded, because the Prophet, peace and blessings be upon him, made an error in recitation and was opened up to. If the Imam makes many errors, the solution is for him to recite from what he is certain of his memorization and to review his recitation before the prayer, not by abandoning the sunnah of opening up.