I am 23 and have been with my girlfriend for 4 years now (she is my first official girlfriend I have ever had). The biggest reason, I believe, that we have remained together this whole time has been companionship: we like to go to new places together all the time and explore fun new restaurants, malls, etc. together. Basically, we are like best friends, are physically attracted to one another, have very close communication with each other (open about everything), and both enjoy each others presence in public as well, considering the fact that we are both fairly good-looking individuals. Now aside from the Romeo and Juliet lifestyle described above, there are some personality traits that she possesses that have bothered me since I first met her. For example, I see the following insecurities in her:

1. If there is a mirror, she will check herself out in it 100000000 times (not sure if that's normal or if all girls are like that). She is SO obsessed with her looks!
2. Everytime we go out and meet a new couple, once the event is over and we are driving back, she will CERTAINLY start to say something negative about the girl (such as, "Well they were a pretty cool couple, but I don't know, Megan is a very weird girl, she's so...". This makes me think she is insecure about herself and wants to eliminate potential competition by trying to make me think badly about all girls around us. In general, she will whine, complain, and put things down around her all the time.
3. She loves attention! Okay, I know they say all girls love attention (and this is also true for many guys as well), but at parties or social gatherings, she LOVES to talk a lot and be the center of attention (and she even speaks in an above-average high volume, as if to ensure her voice will be heard above all).
4. In general, maybe 90% of the conversations she holds are all about "I, I, I, me, myself, ..." It gets to a point that I just get SUPER annoyed. In front of others, she is not humble AT ALL and will say things like "I am so smart...," "I have always been good at...," and other cocky, non-humble statements. I have told her this before, and she justifies it with "no, it's not that bad, in this world you have to sell yourself so they don't think badly about you." If it's a job interview, I understand, but for everyday social gatherings, I don't buy that. I hate how she tries to prove her worth to everyone.
5. In public, she laughs alot (I don't mean at jokes), but even at unnecessary times (the way people do when they are uncomfortable or insecure and are desperate to fit in).
6. She tries to be too friendly with new guys that she meets and in my opinion crosses the line such that they feel comfortable to start flirting with her or talking to her inappropriately (she makes it almost too easy for them, then turns around and rubs the situation in my face). To top it all off, she then comes to me and explains with a big smile what happened and how a guy at work was trying to flirt with her, etc. WHY WOULD YOU TELL YOUR BOYFRIEND THIS? Besides the fact that yes, I do get a little bit jealous hearing all about that, what disgusts me even more is how she is insecure and always has this urge to share stories like this (or perhaps sometimes even make some up) to perhaps prove to me that she is very likeable (even though I ALWAYS treat her with utmost respect and never make her feel unwanted).

Earlier, I did mention that we have a great open/honest communication with each other. Because of this, I have talked to her about each and every single bullet point mentioned above and told her how I despise each of them. For all of them, she agreed 100% and said okay, it won't happen again, but it all continues to happen. Seeing how this cycle happens again and again, I am not sure: am I just being too picky and stressing out about pointless things, or are these real concerns that I should be aware of? The last thing I want is to live a stressfull life by being stuck with a wrong girl who confuses me by frequently saying "I LOVE YOU SO MUCH!"

Please, any honest opinion/guidance you guys can give me, I will greatly appreciate it. Don't hold back on any thoughts!

Thanks...