I personally dislike living in Non-Islamic country and want know if its harm to live in Non-Islamic country. Can you all please provide me some Quran verses and authentic hadith in all your answers? Can you please also include some advantages and disadvantages of living in Non-Islamic country? I also want to know if something is not stated in the Qur'an or Sunnah as haram or halal, could well-qualified Muslim scholars have the power to declare whether it’s harm or halal? Ex: Smoking, it would make sense if a well-qualified Muslim-Scholar said it was Haram, because there is a an authentic Hadith that states, “ Anything that cause haram in your body is harm.” And we all know that smoking causes cancer and other diseases.

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

Know that Allah, The Exalted, has not given any of His creatures power or authority to make anything Haram or Halal except Himself, not even His Messenger (SAW). A Messenger's duty is only to inform The Divine Messages.
Allah says: {Say (O Muhammadto these polytheists): "Tell me, what provision Allâh has sent down to you! And you have made of it lawful and unlawful." Say (O Muhammad SAW): "Has Allâh permitted you (to do so), or do you invent a lie against Allâh?"} [10:59]
This means that Wahy (inspiration) is the only source of Halal and Haram as stated in the Qur'an and Sunnah, and the scholars' duty is to guide people and teach them what is Halal or Haram as mentioned in the Qur'an and Sunnah.
Then, those scholars who believe in the prohibition of smoking depend on Shari'a generalizations and their indications as stated in the Qur'an: {…..he allows them as lawful At-Taiyibât [(i.e. all good and lawful) as regards things, deeds, beliefs, persons, foods, etc.], and prohibits them as unlawful Al-Khabâ'ith (i.e. all evil and unlawful as regards things, deeds, beliefs, persons, foods, etc.), ……} [7:157]
Also, in the Sunnah: 'There should be no harming nor reciprocal harming' { Ahmad and others].
As for living in a non-Muslim country please read the Fatwa:
81464 and 81642.
Allah knows best.