Does she think of me as a friend or something more?

(Sorry about the long post)
This problem has been bothering me for the past 7 years. I've been good friends with this girl since high school, we did a lot of things together, I realize that I have feelings for her one day.

I held back, because I'm not sure about her gender preference. I was even more determined to keep my feelings hidden when she mentioned she is not a lesbian. There was this other girl that likes her, and my friend seemed very bothered by that. But then she wrote in her blog that she might be bisexual but unsure. I got hopeful that she might make an exception for me, I tried to look for signs that she's interested, but except for the few times that she hugged me tightly for no reason, I could find none.

Later she went to study abroad. We talked less then, we barely contacted each other. I heard from another friend that she had been in a relationship with 2 guys while abroad. (but she broke up with them). I tried to get over her then, knowing that it's highly unlikely that we'll ever be together.

She returns to the country sometimes, we hung out a few times for the past few years, my feelings are still there, but they are far less intense. By the way she acts around me I'm sure now she just considers me a friend. She didn't initiate any physical contact with me, we just talked and have drinks. But then her behavior got confusing during our latest meeting, she got more touchy with me.

We hung out with a group of friends several times, I realize that when I walk or sit next to her, she puts her arm around my shoulder or link it with mine. While we were at a restaurant, she suddenly rubbed the top of my hand with hers while she talked. She hugged me from behind and massaged my shoulder. She even joked about being in a relationship with me.
Are these just normal friendly behavior for girls? I don't know anymore. Why would she suddenly act like this when we barely even talked for the past few years? My feelings definitely returned when she touched me, now I think about her so much that I couldn't sleep and got physically sick.
She's about to leave soon, should I ask her out and tell her? I think the next time she returns would be months later, I don't think I could stand guessing any longer...