Yes, one day people will be capable of travel by teleportation. There is current research into the subject. Humanity has a history of dreaming big and then accomplishing these things. A century ago, no one thought it possible for mankind to ever walk on the moon. It is naive to believe it is impossible to teleport when so many things once thought impossible are now occuring.
We will some day achieve teleporation. In fact, we already have over a very small distance and on a tiny scale. But I think with humans and machines, teleportation will have to be done with a worm hole that opens up and we "jump" through it. I don't think we can just be obliterated and reassembled somewhere else.
I don't think it will happen in the next century but if technology continues to progress at a rapid rate I believe that there will be a certain point that traveling by teleportation is a thing that can happen realistically, I don't think I will ever be alive to see it happen though.
Teleporatation will be impossible to ever master for an organism so complex as a human being. There are many millions of things which would need to be replacated perfectly. One small error could lead to sickness or even death. Maybe it will be possible for things like sand or fruit where some little mistakes won't matter.
I don't think so. It is hard to predict how much technology might progress in the future, but the idea of mapping and breaking down every atom in the body, and recreating it somewhere else, would appear to be so complex and problematic, that it is hard to imagine how it could ever be possible.