All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
Your question included two different matters:
The first matter: Living in a non-Muslim country, this is forbidden if a person is not able to practise his religion and is not safe from being afflicted and tempted in his religion. However, if he can practise his religion and is safe from being afflicted in his religion, then it is dislikeable to live in such a country. Our advice is that one should not go to a non-Muslim country except for a need like seeking knowledge, or calling people to Islam, or for medical treatment or the like. For more details about living in a non-Muslim country, please refer to Fatwa: 81642.
The second matter: Helping the people who want to obtain a visa to travel to a non-Muslim country: this is depending on what has already been said, if the travel to that country is permissible then helping them is permissible, and if it is not permissible then it is also not permissible to help them as in such a case you are helping them in sin and transgression, and Allaah says (interpretation of meaning): {Help you one another in virtue, righteousness and piety; but do not help one another in sin and transgression}[5:2].
Allaah knows best.