What are Romeo's feelings and actions toward Juliet?

Romeo is in love with Juliet, or at least claims to be. Their love, however, is problematic in the sense that Romeo has only recently been enthralled with another woman, Rosaline. It wouldn't be nonsensical to assume that if Juliet hadn't been around, Romeo would have fallen in love with another woman just as easily. It's important to remember that he's a teenager, and probably doesn't have a strong awareness with regard to what he wants. But offering him the benefit of the doubt, Romeo is so enraptured by Juliet that he's willing to risk his life to see her at her balcony window, to propose marriage to her and to go through with the deed, to die when he believes that Juliet is dead herself. It seems he is unable to live, or even function properly, without her.