[Mr. K]

you assume we KNOW all the laws of physics

There may still be things to learn, like gravity wave propulsion (not prohibitted by Einstein’s equations)

[Tenacious 1]

you assume we KNOW all the laws of physics

Science is dumbfounded by gravity to this day. In other parts of the universe, current theories suggest gravity may behave differently. Of course, a lot of those theories are formed to patch holes in still other theories, usually on the way to figuring out where our universe came from.

[MHGinTN]

Quantum entanglement indicates that at least at some spacetime level instantaneous communication can happen. Einstein's speed limit is supposedly on communication, but entangled particles disobey that limit, so it is obviously not hindering two entangled particles. Now the trick is to establish a much larger state of 'particle' and let 'er rip!

BTW, if you could see the entire Universe from the outside, it would all be nothing more than a particle in a larger context. If a bubble can be established inside the Universe which isolates the inside of the bubble from the spacetime Universe of our experience, then all of the Universe is simultaneously accessible to the ones 'inside' the bubble.