Both of those seem like reasonable desires. Nobody's disputing that he's the creator after all. It looks to me like copyright law is broken, but I guess parliament won't be rushing to fix it to plug gaps for edge cases involving anonymous street artists.
What surprises me more is that there isn't a wave of faux Banksys flooding the market - sure the artist has a style but it's not absolutely unreproducible. And if, in legal terms, nobody's Banksy doesn't that mean that we're all Banksy?