Is it permissible to insist to one's father that he accept marriage to a paternal cousin, despite his refusal for religious, social, and material reasons, and the suitor's belief that he can be guided after marriage, in fulfillment of the hadith, "I have not seen for two who love one another anything like marriage"?

It is not permissible to accept marriage to someone who only prays Jumu'ah, smokes, and frequents cafes, because abandoning prayer is a major sin. Marrying someone who is not righteous, hoping for their guidance, is an ill-advised gamble with undesirable consequences, and love should not be at the expense of religion. The young man must be informed that the rejection is due to his shortcomings in his religious practice. If he rectifies himself and remains steadfast in that, then his acceptance can be considered; otherwise, leave him. True happiness comes from faith and righteous deeds, not from a marriage not based on obedience to Allah. Furthermore, your cousin is a stranger to you, so a relationship between you before marriage is not permissible.