A question for the guys.. i think its weird..?

Hugs alone are not considered flirting to me. Especially if its just a girl I know well and talk a lot with. In your case though if the hugs last as long as you say or think they do then maybe you have something going for you. I honestly would never hug a girl that I wasn't dating from behind either just because its risky and if she doesn't like it, it would be awkward. If you do all the other flirting then you probably have a connection and from how you posted it, to me it really seems like he is into you. The whole birthday thing and the arm around the side are good indicators that he likes you a lot. I say go for it if you were planning on asking him out. Or at least start moving in that direction in your conversations to see if he is as into you as you think he is. So my final synopsis is that hugs alone are not an indicator of "liking" someone but if they seem meaningful and come along with other forms of flirting then you probably have something going for you.