It's strange isn't it, that I reach such different conclusions. Not accepting dimensions for example, although we all know they exist each time we open a box

Blame that on 'c', Einstein and relativity. You might say that strings and loops look at it in a similar manner though? See, if I'm right in that dimensions is a wrong concept then a lot of the definitions used becomes wrong too. And the reasons why Einstein never could find a mathematical way to describe this fifth dimension he thought to carry the four we observe becomes more understandable. He went out from a universe making sense, even though 'c' was there. And he went out from an idea of a universe 'containing us', so looking at the universe he found, time dilations and Lorentz contractions, he needed a construct in where there was no need to Lorentz transform anything.

I just run the opposite direction with his concept, assuming that we already had a universe without time dilations and Lorentz contractions

That's the 'strictly local' point of view. Problem with it is that it doesn't in-cooperate a clock, and there is no ruler to it. The clock and ruler comes into existence, interacting with other frames of reference. You could call it 'time less' if you like. But it's not where you are, is it? So Einstein was right, still is, one hundred years later.

We measure relative clock and a ruler. We define both locally idealized. To do it we must assume them to exist, even though we can't measure it. Any other way, and you have no more repeatable experiments.