It's good to understand that kids get easily wrapped up into feelings of love; especially with all those hormones. They make promises they won't keep. Don't expect them to keep them; not because they're liars: just because they're wrapped up in the heat of passion and emotion and don't foresee what is often mistaken as "betrayal." I, too, would get wrapped up in its heat at younger ages and said silly, misguided things, and made silly, misguided promises. Such naive claims and promises are written in water. They're not mean, just naive. That tackles long-term promises.
Attraction and Lust are often mistaken as love. It can be claimed as love and felt as love, but it will fade much faster than love. Again, one is not a liar if such feelings fade: one is simply unaware. I am, currently, at a point in my life that I am struggling to distinguish between the various types of love; Commitment, Passion, and Intimacy. Again, you should never expect too much from people. After all, we are only human.
If I may answer your questions...
1. Yes, though I may not know you very well, I know you're a person, and therefore special.
2. I would I could be there for everyone, but I won't sound unrealistic. I'll be there when I can.
3. I would.
4. Well, if you truly are lied to, don't dwell on it. This just means someone isn't "the one." Let go of any negative emotion and keep moving forward. Don't let anyone hold you back.
5. Never intentionally, no.
6. Woah, slow down...I barely know you xD
(jk of course...)