1- I'm not really sure if dolphins helped Nikki to speak. In fact, I don't believe that they helped him. However, there are hundred of theories which support that swimming with dolphins has got positives consequences.
2- Of course the media exaggerated. From my point of view, Nikki was in a confortable enviroment at that moment, so he wanted to tell other people how well he was in the water. Maybe, he hadn't been such interested about something until that moment.
3- I've heared several kind of histories about animals, but I've never heared one with these characteristics before.
4- Look what happened in Zaragoza recently. A common family achieved to raise an enormous amount of money to try to help his son (he was terribly ill). I suppose I'd try to show my case on all TV's channels and on newspapers. Society is open-minded when people read or watch this kind of news.