Hey there. Ok, this one's quite easy, I'll give it a shot.
Q1: Is he interested?
A: He definitely is interested in some way. If he wasn't, he'd not be looking at you that much.
From what you described, it's hard to be certain whether it is a positive kind of interest (he finds you cute) or a negative one (he looks at you because he can't believe how ugly you are).
I guess I suggest you just proceed carefully - once you have more contact, you'll find out which one it is quickly. (If he is nice to you, he likes you.)
Q2: Why does he have a blank expression on his face?
A: This is a sort of defect that is found often in people today. They are just unable to express their emotions. The connection between heart and face is lost. This is a product of upbringing or some traumatic experience.
When you get closer to the guy, he'll find ways to express his feelings. Just be a little patient, stick around him and have trust in the process.
Q3: Why does he turn his head away so quickly?
A: This can have two reasons. Looking into your eyes may just be too intense for him to bear, so he looks away.
Or, it can also be a defect. Bad upbringing causes some children to "learn" that it is "wrong" to stare at someone. So they are embarrassed by eye contact, and they look away.
All in all: I say, you might have a good chance with this guy. At any rate, there is interest on his part. Whether the two of you will be able to get close to each other: Well, I don't know. You could certainly give a try, I'd say.