Arguably, yes, since in bittorrent downloading content is directly tied to distribution of content.
By torrenting a work you own in a different format, you are (potentially) also distributing that work to someone who doesn't already own a copy.
SO just downloading without uploading should be fine?
I'm no lawyer but I'm sure someone could make that case. The torrent peer swarms don't like that though, and I think most clients tend to penalize that behavior (leeching).
I'd wager so since you own a book, not the content of the book. But the law is a funny thing.
Yes it is. But illegal might be the wrong question. Is it unethical?