What is the ruling on the social security imposed on a Muslim, opening an account in a usurious bank to receive grants or transfers, missing prayers at the university or in congregation due to expulsion rules, delaying prayer or combining the two prayers (Dhuhr and Asr or Maghrib and Isha) due to examination circumstances, addressing a disbeliever in the plural form and greeting him with a non-Islamic greeting, and depositing an amount in a usurious bank to obtain a visa?

Any knowledge that benefits the Muslim community is an act of worship and a communal obligation (fard kifaya), provided it is undertaken with the intention of serving Islam and Muslims. A Muslim in a land of disbelief must maintain their rectitude and obedience, avoid discord and forbidden mixing, lower their gaze, and seek help through marriage or fasting and lawful activities. Maintaining congregational prayer is strongly emphasized, and one must seek a way to perform it in congregation, whether in a mosque or elsewhere. It is permissible to delay Dhuhr prayer to combine it with Asr during times of necessity, such as exams, or to perform it at the very end of its chosen time. It is permissible to address a non-believer using the plural form and to greet them with what is customary, but without using "Salam."