Could the brutal treatment by the father and his accusing his wife and daughters of their honor after his second marriage be the effect of magic, especially with the difficulty in livelihood and marriage?

If the father's behavior suddenly changes without an apparent reason, he might be afflicted with sorcery or similar. The best cure for this is the legal Ruqyah. You must treat him with kindness and dutifulness, and beware of disobeying him. You can seek help from some virtuous people to advise him. The difficulty in sustenance and the delay in the sisters' marriages do not necessarily have to be due to sorcery; rather, it could be a trial.