People who use Euclidean intuitions to frame their comprehension of physical reality often interpret the physicist’s statement that “nothing can move through space faster than the speed of light” [i] to mean that humans have not yet found a way to boost something beyond this speed. They tend to respond with the suggestion that advanced technology will eventually enable mankind to overcome this restriction, but they have missed the point entirely.
I think you are looking for an argument where there is none.
I too, agree that there is no way to exceed the speed of light through conventional travel of any sorts, whatsoever. This isn't up for debate, because we can't, and the science is sound.
What we don't understand is the answer to 1) above. Nobody knows this. It is one of the most profound mysteries in all of physics.