Is it permissible to study Islamic law at university with the aim of obtaining a well-paid job, knowing that I do not intend to teach people or become a teacher? And does this contradict the Hadiths that forbid seeking knowledge for worldly gain, and the Hadith that permits taking a wage for teaching the Book of Allah?

Enrolling in the Faculty of Sharia for the purpose of learning, even with a salary, is permissible. What is forbidden is for the intention to be purely for ostentation (riya') or for worldly gain. The Hadith: "I am the richest of partners, above any association [with others]" refers to ostentation, not to this situation. So, whoever strives to achieve obedience to Allah and also gains spoils, it does not harm him, because that is not ostentation. Similarly, one who performs Hajj with the intention of trade.