Would the husband be sinful for temporarily preventing his wife from going to memorize the Quran, if that would avoid existing family problems between the wife and the husband's family, and allow for the resolution of the wife's shortcomings in household chores?

A wife is not permitted to leave the house without her husband's permission. There is no sin upon him if he prevents her from going to a Qur'an memorization class, unless it is for memorizing Al-Fatiha and she has no one at home to teach it to her. It is preferable for him to help her memorize the Qur'an if her going out does not entail any corruption. It is the wife's right to live in an independent dwelling, and she is not obligated to serve her husband's mother. Scholars have differed regarding the obligation of the niqab, but the wife must obey her husband if he commands her to wear it. The relationship between the spouses should be based on affection, mercy, understanding, and overlooking minor faults.