Is it permissible to evade customs duties and taxes, knowing that these governments use the funds in ways that do not conform to Allah's law? And what is the ruling on importing materials that these countries prohibit, despite their availability both locally and through import?

Smuggling prohibited goods by the state is impermissible if the public interest necessitates their prohibition, such as if they are harmful or of poor quality, or if they negatively impact local products and harm the nation's economy. However, if there is no public interest in prohibiting their entry, and the prohibition is for monopolistic purposes and to harm the consumer, then there is no objection to smuggling and importing them.