1. I'd say the poster is the author since his nic is the same as the author. At least he didn't try to fake a false review, but I think it would have been more polite to fully disclose it's his book

2. I'd call it more of an 'advertisement' than 'spam' since it is at least on topic as opposed to Viagra, pharmaceuticals, new cars, time shares, or multi-level marketing

3. Maybe leave it here for awhile to see if there are any reviews posted by other members?