What's a good thesis statement on how Romeo changes in Romeo and Juliet?

Thesis: Throught Romeo and Juliet, Romeo fails to advance beyond his passionate, yet irrational and rash self, which leads to his eventual suicide by Juliet's tomb.

It's tough to argue that Romeo is the hero of a play when it ends with the teenager's suicide. While Romeo is clearly the play's protagonist,he remains, regretfully, a static character, and doesn't change. 

He begins the play pining over Rosaline, who "hath forsworn to...

Thesis: Throught Romeo and Juliet, Romeo fails to advance beyond his passionate, yet irrational and rash self, which leads to his eventual suicide by Juliet's tomb.

It's tough to argue that Romeo is the hero of a play when it ends with the teenager's suicide. While Romeo is clearly the play's protagonist,he remains, regretfully, a static character, and doesn't change. 

He begins the play pining over Rosaline, who "hath forsworn to love, and in that vow / Do I live dead that live to tell it now." Romeo goes on to describe how he'll never see another like Rosaline and wishes Benvolio can teach him not to think so that he did not have to be so sad.

Romeo's relationship with Juliet, including the dramatic balcony scene, are the actions of an irrational teenager. Drunken by Juliet's beauty, Romeo climbs her balcony risking his life if caught by her father's men, who are mortal enemies to Romeo's family. But this doesn't stop the boy, who after seeing Juliet once and dancing with her once and kissing her once has fallen madly in love. Romeo is full of hyperbolic statements when Juliet delivers her monologue while standing on the balcony. He calls her a "bright angel" and says she's "as glorious to this night" and then, again, to "a winged-messenger of heaven." All of this, while sweet, indicates irrational thought. 

Finally, Romeo kills himself when he sees Juliet dead in her tombstone, but not before dispatching Prince Paris in a passionate duel. There are many other ways in which Romeo could have handled this. For example, he could have grieved with Paris instead of fighting him and killing him. However, his rashness leads him to murder and then it leads him to kill himself.

There are other events throughout this play that illustrate Romeo's irrationality and rashness, including his fight that ends with the death of Tybalt. However, to argue that Romeo "changes" throughout this play is a bit disingenuous.