Dear Robert,
You write: ''If you define the Universe as ''the totality of everything that exists, including all matter and spacetime'', then there is nothing but the Universe. Therefore you cannot logically use the idea of "outside" to postulate an "edge of the Universe" if there is nothing else but the Universe''.
1) First, vacuum holes do not contradict the statement ''there is nothing but the Universe''. A hole is nothing - no matter, no spacetime, therefore it is correct that ''there is nothing but the Universe''. If you add a hole (nothing) to the Universe then its matter-energy remain constant.
2) I can show this statement is wrong ''Therefore you cannot logically use the idea of "outside" to postulate an "edge of the Universe''.
According to the theory, the Universe is a MATERIAL object composed of matter and spacetime but not a mathematical abstraction. You know that all material objects finite in volume have borders. Since the Universe as a whole also is a real object, it must have a border, at least in form of a point. And the border is another name for vacuum holes. You see, I can logically use the idea of "outside" to introduce an "edge of the Universe.
To prove me wrong please show me an example of a material object (finite in volume) without borders.
''If there is nothing else but the Universe then your ''hole'' cannot exist, not even temporarily''.
It is not correct. I repeat, if you add a hole (nothing) to the Universe then its matter-energy remain constant, and you can say: ''There is nothing else but the Universe''; Even if the Universe has holes, ''there is nothing else but the Universe''. The hole is nothing.
You write: ''Regarding ''the nature of motion'', it is possible to explain ''discontinuous trajectories'' by appealing to the nature of matter alone.
Maybe you know other explanations for discontinuous trajectories. However, my explanation is better because it can explain motion, gravitation, inertia, teleportation and quantum phenomena in the same model. I'm sure that your variant cannot explain, for example inertia. Therefore, my explanation with holes is better.
Regards,
Constantin