1) An example of what can happen when you combine genuine physical skills, stooges, highly suggestible marks, the right kind of pseudo-scientific mumbo jumbo and cheap technology to give the illusion of one thing happening when actually it's something else entirely. Try watching some Derren Brown.
http://www.youtube.com/watch?v=5WnZkzjweCE&feature=youtube_gdata_player
2) Again a combination of mumbo jumbo and physical principles. The dummy test is irrelevant as the actual subject was not hit as hard, and the amount of force transferred depends on how far along the bat the contact is made. In the actual hit it's so close to the handle that anyone with decent conditioning and footwork could take that hit. In fact I'd say most full contact kickers take worse at most training sessions. The dummy and the 'scientists' in this show are just there as convincers. The short bat principle also applies to the wood across the back. The wood breaks only due to the momentum of the free end. The spear to the throat can be achieved through solely physical training too, nothing to do with chi - the thin layer covering the oesophagus area can be stretched to incredible tension when properly trained, making it strong versus a pushing force. Versus a stab, the story would be very different. These are all parlour tricks.
3) Utter nonsense. How exactly does electromagnetism affect a plastic straw, again? Bad science followed by a cheap illusion I can replicate using invisible thread for 50 cents. Wonder why it's so dark in the room when he's filming a video. You'd think he would want us to see what he can do. Come to think of it, it's pretty dark in a lot of these chi videos on Youtube. And there are a lot of tablecloths, unproven random assistants, and testimonies from 'friends' or 'students'. There are even a few vids of chi 'masters' entering full contact and getting their clocks cleaned. What does that tell you?
Apologies for living so relentlessly in the real world George, but I'm not seeing anything here that doesn't scream fake jake. I'd like to believe that this is some kind of supernatural power, but it's just so clearly not that any sane and rational person has to reject that idea.
*Addition: Derren Brown recreates a no contact chi punch scenario. He does not profess to have any supernatural powers:
http://www.youtube.com/watch?v=dmVfHZgHMUk&feature=youtube_gdata_player
Gnarlie