i believe that he did value looks over personality, and yes, she most definetly WAS a rebound from rosaline. tybalt was her cousin, and the person she was told to marry was paris. she didn't discover this fact untill AFTER she had married romeo, so it wasn't that she didn't want to get married to someone else. you are right, they didn't know each other when they eloped, but in their minds, it was the right thing to do.
Stubborn means to have determination to not change one's attitude or position on something. A good time to be stubborn is when something compromises your morals.