Which thesis is better for Romeo and Juliet?

As theses on fate go, your second is the best. If you believe that man's destiny is to be controlled by the actions of a higher power, then Romeo and Juliet are a great example. However, I believe that Romeo and Juliet were completely in control of what happened in their lives due to the choices they made. The part of your thesis that is strongest is your assertion that the feud between the Capulets and the Montagues is pointless and destructive. Life is enough of a challenge without constantly worrying about how your actions will be perceived by "enemies" of your family or yourself.