Not quite. The most basic description of science is that it deals exclusively with testable ideas, ideas that can be compared to reality. And if reality disagrees, the idea is abandoned.
So it's not that "nothing else exists" but that untestable, unfalsifiable ideas aren't a matter of interest to a scientist.
> It is a thesis of mine and as of right now there is no disproof. [emphasis added]
There's another important distinction between science and non-science -- in science, an idea without supporting evidence is assumed to be false (the null hypothesis). To a non-scientist, ideas that haven't been disproven are assumed to be true (as in your example above). That's a big difference -- it's why nonscientists accept so many unsupported ideas.
Because of the null hypothesis, scientists are described as skeptical of ideas unaccompanied by evidence. This posture is sometimes looked on as a handicap -- until a jury is empaneled, at which point a variant form of the null hypothesis is explained to the jurors (innocent until proven guilty).
It all depends on how important the outcome is. If it's just a philosophical debate with no practical consequences, then believing anything does no harm. But when our lives or our health depend on the result, the null hypothesis has it all over the undisciplined approach.