I don't think the ink would harm him, but I would stay away from the colored advertisement sections.
I don't think there's too much you can do to stop him from tearing up the carpet. PDs dig, it's a natural thing. Keep a close eye on him and tell him "NO", but I think it's going to be hard to stop that habit completely.
I wouldn't give him the yogurt drops because I believe they have a high sugar content. One every other week or so shouldn't be too big of a deal, but I definitley wouldn't make it a daily treat.
Hope this helps.