What role did Friar Lawrence play in uniting Romeo and Juliet? Was he successful?

If you were to consider Romeo and Juliet as united in death, the afterlife, I would have to say he was successful. However, the Friar far oversteps his bounds, especially as a man of God, when he meddles in Romeo's love affairs. He questions Romeo in Act II, Scene 3: "Was thou with Rosaline?" It is as if the Friar, in his bumbling way, is living vicariously through the teenager's life. In this same scene, Romeo confesses he no longer loves Rosaline, it is now a Capulet, Juliet, who hold his heart. The Friar, without question, immediately becomes part of their secret affair:"I'll thy assistant be" (2.3.90).

Later, as we know, the Friar uses his holy power to secretly marry the two lovers in hopes of joining the feuding houses: "...you shall not stay alone till Holy Church incorporate two in one" (2.6.37). Unfortunately for the Friar, he is instrumental in the deaths of Romeo and Paris, and his only solution for Juliet prior to her suicide is to "Come, come away...I'll dispose of thee among a sisterhood of holy nuns" (5.3.154-157). What young girl in love, with her lover dead before her, would choose to go to a nunnery? Thus, the Friar may be motivated by good intent, yet by meddling in the teenager's lives, he plays a large role in the death of the innocents!