Very nice although honestly I don't like the site's design. But concerning with the ad placements, they are put correctly. Therefore, you're safe. Good luck!
Its legit, but dangerous. Most click frauds will happen. Also your content must be more and more. If you have less content, google will assume only money make site. You should have more traffic even.
3 is Maximum, I think. But if any big publisher have done special agreement with Adsense then they will allow more.
Google does not penalize multiple adsense units. However, if you serve too many units on a page, it may opt to only populate the first few with ads and leave the rest blank, or run public service ads in them.