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.
Residing in a non-Muslim country is not permissible except with the ability to establish one's religion. Therefore, if such a person is unable to establish his religion in that country, then he is obliged to migrate from it to a Muslim country.
In case he is unable to migrate and he is obliged to stay in that country, then he should fear Allaah as much as he can and do what he is able to do but he is exempted from what he cannot do because Allaah does not burden a soul beyond its power. For more benefit, please refer to Fatwa 86405.
Besides, he is not obliged to pray in the mosque according to the view of the majority of the scholars but he is obliged to pray in congregation. So, if he has a sound reason for not attending the congregational prayer, like if he fears for his own self or his money, then he is permitted not to attend the congregational prayer.
Again, he is not permitted to combine two prayers except with a sound reason. In case he is harmed by leaving his job and he is obliged to stay in it, then he is permitted, Allaah willing, to combine between two prayers. For more benefit, please refer to Fataawa 82264 and 88316.
On the other hand, he is not permitted to eat from the earnings of a person whose all money is ill-gotten money except according to the necessity. In case he gets any lawful earnings, he should first spend on himself. In addition to this, marriage is among one's basic needs, so he is not obliged to spend on his family if he needs the money for his marriage.
In any case, he should advise those people who gain ill-gotten money and explain to them the seriousness of what they are doing. If they are able to gain lawful earnings, he is not obliged to spend on them, and he should spend what exceeds his needs on the closest poor relatives who are unable to earn their living and then those who come after them in degree (of closeness to him).
Also, he is not permitted to keep the ill-gotten money that he saved, rather he is obliged to give it entirely in charity as it is the right of the poor and destitute, or that he should give it for the general interests of the Muslims.
As regards the expiation, it is an obligation to give it in the form of food according to the view of the majority of the scholars . So, you should buy food and give it to this poor person to own it or to any other poor person, as clarified in Fataawa 86943 and 90726. The fact that this person does not pray is not an impediment to giving him the expiation according to the most preponderant opinion of the scholars as he is considered as a Muslim according to the view of the majority of the scholars . For more benefit, please refer to Fatwa 89661.
Finally, you should know that whoever has to make up for days he failed to fast in Ramadan, the expiation is not sufficient for him unless he can never make them up because he has a chronic disease due to which he is unable to fast.
Allaah Knows best.