While I do think it would be a bad idea, it would be possible for the OP to hide a good amount of his trading income, especially if he properly maintains his privacy
Trying to use bitcoin to break the law is a bad idea in general for lots of reason.I surely hope that isn't what the OP had in mind.
I don't think it is. My impression is that he is trying to avoid using government fiat as much as possible, however there are not enough businesses that accept bitcoin for this to be a viable option yet. I think a better approach would be a greater push to get more merchants to accept bitcoin so they can see it's cost advantages