Hancock isn't a scientist, and has never claimed to be. He presents himself as an investigative journalist. What he explores in his work are a series of "what if" questions that science either can't disprove, or hasn't been actively researching, for whatever reason.
The show is beautifully shot and produced, and provokes some interesting thought experiments. Besides "free thinkers" making an appearance, there are also "mainstream" scientists from renowned institutions around the world, who seem to side with Hancock in many ways.
If the show does nothing but raise more public awareness about these topics, it might lead to funding actual scientific research in some of these sites, which would be a good thing.
So far from being a "dangerous show", it's actually an interesting and well-shot documentary. People who see it as proof of anything factual are likely already conspiracy theorists, and are a lost cause for logical thinking anyway.