Anon 1 - If you've kept in touch with this guy for so long, even at this rate, he must at least like you as a friend. So therefore, become better friends, start doing more stuff together, then see where it goes. If he's shy, then you are going to have to take the lead. Also, do you know any of his friends - maybe you or one of your friends can ask his friend about his situation and any potential feelings towards you to help work things out?
Anon 3 - Does you teacher have rules that they must keep to regarding seeing a student, etc? If so, he might not be able to do anything even if he wants to! If you think that it maybe possible that such rules don't apply/don't bother him, then I'd suggest some personal tuition, followed by buying him a drink to thank him for his help, maybe? If he's hinting, and you don't think he's sure how you feel, the MAKE IT CLEAR!
Anon 4 - Start doing more things together, then try to read her mind, see what she thinks.