Non-verbal signs by the shy guy?

I'm shy, and I think I do a lot of those things.

The actual action itself is meaningless, for me there's no difference in meaning between a nervous laughter and a head tilt.

It all comes down to the guy being out of his comfort zone and these are his reactions to it. If he's acting this way it means he's willing to go through the mental discomfort to get your attention, so it's a good sign.

I'm no psychologist or anything, but I'll try my best to decifer these things.
Head Tilt - Not wanting to be in a situation. Possibly nervous and feels awkward
Sarcasm - His way to crack a joke or trying to be funny.

Nervous Laughter - Trying to associate with people and thinking it was a good time to laugh?

Humming - If he had nothing to say, trying to take up time humming or making some sort of sound.
Eyebrow raise - saying 'whoa' or 'wow' in eyebrow language
Distracted by other Things - ADHD. I don't quite understand this one
Thinking in deep thought - The way a shy guy would think since he is shy he wouldn't want to think and say really what he is thinking, therefore looking like he is in deep thought a lot of the time.

Hmm I think he's just nervous around you if all these signs occur around you. Not really much going in his mind, though. :)