Is it permissible to cook in used utensils coming from Europe, given the possibility that pork may have been cooked in them?

It is permissible to use the utensils of disbelievers, but if it is highly probable that they drink wine or place pork in them, they should not be used except after washing. This applies specifically to the People of the Book and others. There are hadiths that support this, such as the Almighty's saying: "The food of those who were given the Scripture is lawful for you," and also the hadith of Abu Tha'labah al-Khushani: "If you find other [utensils], do not eat in them. But if you do not find any other, then wash them and eat in them." Some jurists hold that using them after washing is makrooh (disliked) if other options are available, especially if they have been used for impurities. In summary: It is permissible to use the utensils of disbelievers. If it is known or highly probable that they used them for impurities, then they should not be used except after washing them. And using them when other options are available is makrooh.