Does the wife have the right to stop her husband from visiting some of his relatives because their meetings involve religious violations?

Couples should advise one another in kindness, and the wife can stop her husband from committing sin by resorting to a kind and tactful approach.

Is the patient who is on dialysis twice a week obliged to observe fasting? Is his fasting on the days he is on dialysis considered valid or not?

Praise be to Allah the Lord of the Worlds.

Dialysis invalidates fasting because of the nutritional fluid used in that procedure, as pointed by specialized doctors, in addition to causing bodies to enter the stomach. Therefore, it is recommended that the patient who had undergone dialysis to observe fasting for the rest of that day, if he is able to, and make up for it after Ramadan. However, if the doctor told him that fasting, at any time, would damage his health, then he must break his fast and pay a ransom against every missed day. We pray that Allah blesses this person with recovery. And Allah The Almighty Knows Best.

Is it permissible for a person who has to make up for missed fasts to fast six days of Shawal(the month directly after Ramdhaan) before making up for the missed fasts ?

Yes, it is permissible for him/her to do so, but it is better that they make up for missed fasts first.

An Arab young man had an illegitimate sexual relationship with a Christian American while she was staying in one of the Arab countries. After she returned to America, she told him that she had doubts that she was impregnated by him. It is worth pointing that it is hard for him to get a visa to the USA. What is the ruling of Sharia on this?