I didn't read the whole thing (sorry) but a couple of points that I want to make...
1. You kissed her on the cheek? I like to call that the kiss of death. Should've gone for the kiss on the lips.
2. The guy on the other reply is right, you're not sexualising it enough. You need to flirt a lot more
3. Movie date, already? No! You can't judge body language on movie dates, and you can't really talk to her much at all
4. Girls sleep with guys after 2-3 dates on average, so you need to make these dates special and unique. Take her to 2-3 places in one night - it shows effort, and makes her feel like you're closer to eachother than you are. It massively increases your chances of getting sex on the first date. Trust me on that one.
Check these articles for help with friendzone, and good dates.
Good dates:
http://ipickupwomen.com/good-first-date-ideas/
Escape Friendzone:
http://ipickupwomen.com/easily-escape-the-friend-zone/
Edit: I've now read it all. You've probably acted too much like a friend, and confused her a little with the gum thing. You should be flirting, calling her once a week for an EVENING date that can lead to sex, planning it 3-4 days into the future, and getting off the phone after setting a definite date. When she friendzoned you, you should have said "Just friends? I'm not interested in that. I think you're an amazing girl. I don't think I can be around you and not be able to touch you, or talk to you about other people that we're dating. Give me a call if you change your mind" then never talk to her again. Either she calls, or she doesn't.
Instead you just went along with friendzone. Why? It's not what you want? Thats why it happens; you let it happen. People will only ever treat you how you allow them to treat you.
Sorry to hear the situation. It happens to the best of us from time to time..
Hope I helped.