Responsibility of taking care of a woman

Q: A man was taking care of his sisters (due to both parents passing away years back). He has now passed away, amongst his descendants there are 6 kids and a wife, of which only 1 baligh son aged 17.

The sister has 4 paternal uncles (papa's) and 3 maternal uncles (mamajees) and a sister. She is not fully mentally okay and needs someone to oversee her daily living.

Eelaa (taking an oath to abstain from having any relations with one's wife)

Q: A man insisted his wife to go out of the country to work with him, and his wife did not want to go because of the environment in the western country, she was afraid that he would go there. In order not to deteriorate in this environment, her husband then told her that if she did not comply, he swore that he would not go near her for four months, and four months had passed, Does it lead to divorce?