All of the main characters seem to indulge in doing things the hard way. Huck doesn't want to be found out, and yet, he keeps returning to the place he's escaped from. Tom, as you've already mentioned, wants to be traditional...... none-the-less, even tradition isn't necessary, as he's already aware of the fact that Jim is free. Another example would be the feud between the Grangerfords and the Shephersons...... wouldn't it simply have easier (and safer) to admit there was nothing left to feud about than continue to kill each other for the sake of tradition.