Theoretically, you can travel faster then the speed of light through warp drive. They already have the solution, even optimized recently to make it more efficient. They just need to find a source of energy to power it, like dark matter, maybe the hadron helps with this one. This does not mean you went back into the past if you travel faster then the speed of light. Only question I have with warp drive is how do they prevent hitting space debris doing this, unless the warp bubble travels with you and causes everything else to move out of the way when moving through the fabric of space.
The only way you as human can go into the future is by taking yourself out of the equation and say finding a nice black hole to orbit like the one in our milky way with your warp drive ship. This way you will see your kids all grown up or the earth change quickly relative to your own time. We may be interested in doing this if the earth undergoes a natural dissaster.
When you become energy, well thats another point of discussion and may be possible to do this, but then you may exist and function totally different from your human counterpart. Maybe energy = spiritual being, and you become part of the energy system that exists all throughout the universe and maybe become one with God.