Near Light Speed Propulsion?

So faster than light is impossible in our space time, despite the fact that it was achieved during the formation of our universe, but thats another subject. Some scientists, one being Dr. Bae, had provided evidence that we can travel at near the speed of light. May not do us well for traveling among the stars, but will help us colonize our own star system and contribute to a number of other applications. Here is the question though, this new technology, which shows great potential, can propel a spacecraft over a hundred km per second, basically near the speed of light. uming we can't break this speed limit, don't the same problems come to play when we merely approach it? The spacecraft itself will gain more m as it gains speed, time will slow down for the traveler(which isn't so bad). I think the technology uses a stationary craft as a launcher,if this is the case, does this theory still apply? Meaning, if something acts as a launcher, and launches something at near the SoL, with no on-board energy source necessary, does the Law still apply? So basically, does this law still apply to near light travel if there is no need for an on-board energy source? Can a person survive the G-Forces(if they apply) or any other side effects of travelling at these speeds in space? If we can overcome the problem of infinite m and energy, is there anything that can stop us from breaking this cosmic barrier? If the answer is yes to any of these questions, it would seem we may have to skip attempting to do near the SoL, and jump right into bending space-time(which is most likely centuries off). It seems even Einstein left us loopholes, and we've learned so much since then. We are now closer than ever to creating an engine that can cruise a spacecraft at near the SoL with reasonable energy usage, question only being whether the human body can handle it and if the effects of going faster than light will still apply, just not as strong, yet, just strong enough. It sure is a confusing topic, any answers that can clear this up would be great. I'm writing a scifi novel, and i'm trying to stick as close to reality as possible with it come to space travel, however, I really would like to approach close to the speed of light in it and Dr. Bae's Photonic Laser Propulsion so far shows the most promise.