Debate whether Romeo is really in love with Juliet or is it because she kissed him at the ball.

I think Romeo is obsessed with Juliet which is a different thing than love. We already saw Romeo's infatuation with the fair Rosaline in act 1 sc 1. Now Romeo has quickly switched to a new "love" or perhaps lust in Juliet. Romeo's tragic flaw is his obsessive attachment to what he desires. Really, he knows very little about Juliet other than he is attracted to her. I wouldn't call it love.