In Romeo and Juliet, in what ways is Romeo a hothead?

While Romeo is too preoccupied with love to be involved in the fray of Act I, in Act II he is impetuous as he climbs into  Juliet's orchard and later rushes to the Friar to have h im marry him and Juliet; however, he clearly displays a choleric nature in Act III when his friend Mercutio is slain by Tybalt.  Romeo is enraged as he sees Tybalt:

Alive, in triumph! and Mercutio slain!/Away to heaven, respective lenity,/And fire-eyed fury be my conduct now!(III,i,104-106)

Here, he then slays Tybalt in his rage.  Then, when Romeo learns that he is banished from Verona, he flings himself on the floor of Friar Laurence's cell, weeping for himself.  Friar Laurence tries to get Romeo to listen to him:  "Thou fond mad man, hear me a little speak" (II, iii,  ). When Romeo will not listen, the Friar scolds him, but Romeo says that unless the Friar is he, the priest cannot understand. After the Nurse arrives, Romeo learns of Juliet's torment, Romeo wants to kill himself:

Doth my name lodge?  tell me, that I may sack/The hateful mansion (III,iii,105-106)

After Romeo has his secret night with Juliet before leaving Verona, she begs him to stay a little longer as it is not quite day yet; so, he impetuously entertains death again:

Let me be ta'en, let me be put to death;/I am content, so thou wilt hav it so.../Come deth, and welcome! Juliet wills it so./How is't, my soul?  let's talk; it is not day (III,v,17-25)

Finally, when Balthasar informs Romeo of Juliet's apparent death, Romeo shouts "Then I defy you, stars!" (V,i,24).  His servant is concerned, tells Romeo to have patience, and remarks upon his pale and wild looks.  But, Romeo ignores him and rushes to an apothecary for poison.  When Romeo arrives at the Capulet crypt, he cries "By heaven, I will tear thee joint by joint/And strew this hungry churchyard with thy limbs (I,iii,   )  In a temper, he slays Paris who enters the tomb; then, despairing, he assumes Juliet is dead, and drinks the poison. Sadly, it is Romeo's impetuous, hotheaded nature that contributes to the fateful events of the play.