Hello Mr J, welcome to the website (although you're not interested in lucid dreaming [just dream interpretation {or at least for these dreams.}])

Your dreams are simple enough...

#1 The false Elizabeth that drives up to visit you is your inaccurate impression of her, your myth about her. Your friend is probably just some afterthough, but the real one being even more beatiful suggests that you are very much interested in the reality of her, not your myth.

#2 A house is always yourself, and your breaking into her house and doind nothing suggests that your mind keeps going off to her when you don't mean to. You keep having intentions to be with her romanticly when she already doesn't want to.

#3 The Costco is the energy and desire to build a new life, which you want to with her. You hide behind a display, meaning that you hide your thoughts. She comes in, her presence in the dream represents not herself but your feelings for her. You playfully run away but keep running into people you know who then follow you. This must mean that your friends can tell how you feel even though you deny it. She catches you and implies wanting to start a romantic affair with you. You do nothing because you are conditioned to do nothing when these thoughts come to you.
I don't know what the 10 chances might be about, or the number 10.
The guitar may be your ability to romance her and be charming.

That's all I have. Overal it just sounds like a three part dream, your rejection of your own myth for the real person she is, the tendency of your intentions to keep going to her, and your willingness to put a lot into it. Hope it helped.