Does the speed of light mean only the speed of visible electromagnetic radiation?

Does the speed of light mean only the speed of visible electromagnetic radiation?

1) Does the electromagnetic spectrum mean, that the particles are traveling at different speeds?

What means the term "speed of the light"? Does that mean the speed of the light or photons in certain frequencies of the electromagnetic spectrum, which means that something would be travel faster than the visible light could be possible?

There are always people, who are telling us that nothing can reach the speed of photon, and then we must realize that also radio waves are reaching the speed of the light. So that means that electron can travel with the same speed of the light.

But if there would be some kind of radiation, what crosses the cosmic speed limit, that would make possible to make fundamental ideas for space travel. And before we would become too optimistic about that thing, we must realize that one GRB (Gamma-Ray Burst) doesn't make things operating or even the suitable scientific model. And if we would want to benefit this kind vortexes, we must ask, what kind of energy levels that kind of vortex needs to be a benefit in some engine.

2) And would that mean that X- or gamma-rays can travel faster than the visible light?

So the article below this text is telling about the fundamental idea, that the X- or gamma-ray bursts are the light, where the photons are traveling faster than the visible light? In this case, the time would travel backward in that gamma-ray jet, and this would make possible to travel faster than the light.

The thing that supports that theory is that the particles in the gamma-ray bursts seem to go backward in time. But there can be another reason for that, and that thing is that the energy load to those particles would be very high, and when they are flying away from the source of the gamma-ray burst, something would increase the speed of the rotation of those particles. This means that the other side of those atoms or subatomic particles like protons is traveling faster than the speed of the light.

3) Why we would be so excited about that kind of observation? That would give benefit for the photon rocket, which uses X- or gamma rays for giving thrust. 

And if the hypothesis about the faster than the (visible) would be true, that thing makes it possible to create the engine, which would allow traveling faster than the speed of visible light. So if we would create the photon rocket, we could reach the speed of the light, but if we would create a rocket, what uses gamma-or X-rays for giving thrust that could solve many problems with the interstellar traveling.

In this case, we would create the cathode-motor, which would shoot the X- or gamma rays backward. And that thing will make possible to create the extreme version of the photon rocket. But that requires that the X- or gamma-rays would travel faster than the speed of light.

https://www.sciencealert.com/faster-than-light-speeds-could-be-the-reason-why-gamma-ray-bursts-seem-to-go-backwards-in-time

Image: https://www.sciencealert.com/images/2019-09/processed/black-hole-superluminal_1024.jpg