Regarding Mei, agreeing to help an acquaintance is netither smart or dumb, they have a relationship that has not been fully explained, and he might not like the infleunce she has in his sister, but not knowing their relationship you can't say that helping her move some stuff is dumb, specially if she promises help in a situation you need it.
Not telling his friend is neither dumb nor smart, it can be strange that it never came up in chats, but is not like you have to submit a dossier on your family to people you meet at college
He wasn't late this time and even if he was, that makes him unpunctual, not dumb.
Its too soon to say if he is smart or not, he hasn't done much at all. People seem to be reaching...