I'm not sure what you expect people to say. A good writer can make any character interesting.
I think the characters sound a bit cliche. Thieves and beggars and bookworms are common fantasy (I assume that's your genre, but it'd be nice if you would say it) characters and have all been done before.
I'd wonder why Wil has anything to do with some beggar. As an apprentice with a family, the would likely run in very different circles.