Until I was 14 I was completely flat chested and had a bean pole figure. I have short hair too and I was a tomboy. I was mistaken for a boy on several occasions, but none more awkward than when a new girl in the neighborhood pinned me against the wall and started making out with me. She grabbed what she thought was going to be a hand full of cock and balls and she found nothing! I thought she was going to completely freak, but instead she looked at me and asked: "Are you a girl?" I blushed deep red and told her yes. We continued to make out, but it was very awkward and we didn't get past kissing and feeling each other up.
As a boy I used to always try my luck with flat chested girls who were not your classical beauties! I found these girls turned me on more than any other. Freaky!
I'm with #2 i too have often found boyish looking girls extremely attractive, Ever since as a boy i had a small gang of freinds and we had a tomboy in our group who was so like a real boy even peeing standing up that she became a boy in our eyes i did too until we began to sexualy experiment then she was ALL girl, Hence i am now an adult bisexual who still loves the idea of a boyish girl.