Is receiving a salary from a non-Muslim country in exchange for not working — with occasional secret work to cover living expenses — considered permissible (halal) or forbidden (haram), especially if full-time work would conflict with performing prayers and Friday prayer?

Contracts and obligations must be fulfilled. It is not permissible to work without the permission of the competent authorities if the state's regulations prohibit it, except out of necessity if the salary is insufficient for living expenses. One should not take on work that prevents participation in congregational prayers (Jumu'ah or regular) but rather seek alternative employment, as responding to the call to prayer is obligatory. Similarly, permanent residency in non-Muslim countries is not permissible except out of necessity.