I,m sort of with you on this interpretation of 4 dimensional space/time. in that all possible combinations exist at once, this could mean that time in our perception of being a linear dimension that is progressive i is not at all and exists all at once and the termprogressive is in fact meaningless. So when we observe an event we are only witnessing one possible combination.
This in quantum mechanics I think is what is called the Copenhagen interpretation. We then have the problem that as observers we automatically have affected the combination by observing it to begin with I think?