[mxplxxx (OP)]

I think there exists perceived time, related to awareness

Actually, I think perceived time is an emotion. A feeling of "being alive" is likely to be a  a result of a time hormone interacting with a receptor in the brain. Possibly the hormone could originate from the pineal gland which is known to regulate our circadian rhythms. The more "aware" we are, the more the time hormone is generated. This accounts for the fact that we "lose" time when e.g. we daydream and "lose track of time".

In a computer program, a "Timer" object generates "Timer.Tick" events at predetermined intervals. These "Tick" events are used by other objects in the program to handle functions involving time.

[mxplxxx (OP)]

I think there exists perceived time, related to awareness and rate of change of reality systems, and absolute time, related to the absolute speed of light.

Actually, I think rate of change is time related to the absolute speed of light, not awareness.

The universe is composed of systems that interact to handle time-dependent states (see https://www.thenakedscientists.com/forum/index.php?topic=75960.msg575784#msg575784). Systems exist within systems like a set of Russian dolls. As a result, the distances involved in typical functions can vary from system to system. The lower in the set a system appears, the smaller are the distances it has to traverse to carry out its functions. But, the speed of light is a constant for all systems, so the rate of change of a system increases the smaller the system gets. This is how time works at higher and lower scales. The rate of change of e.g. an atom is much greater than that of e.g. a galaxy.

[mxplxxx (OP)]

It is interesting to note that state changes in this universe happen immediately. Which means time is the stillness between events. But what is stillness if not nothing.

[mxplxxx (OP)]

Of course, time and memories are inextricably linked. Without memories there can be no time, just an eternal present. Memories in the brain allow us to process the past and predict the future.

Because of this, it is very likely that all of the objects/systems in the universe are memories, especially given that state changes in the universe are instantaneous. This is especially true of bosons which appear to be recordings of state change events from the past. Bosons (except for Higgs) can be considered to be temporary memories and fermions to be (semi-)permanent memories. Temporary memories are likely not "visible", leading to the possibility that they constitute dark matter. Tachyons can be considered to be future/imaginary memories.

Thus it could be considered that all systems in the universe are, in effect, brains with memories. Networks of galactic clusters are brain-like in appearance. In this way, it could be considered that time is just a a concept in a brain. It is very likely that past memories also exist (somehow) in the universe as spacetime systems, as predicted by Einstein.

Maybe the Higgs Boson/system is a record of all the state changes a system has undergone. This could be achieved if multiple state changes are associated with a Higgs boson/system as subsystems. These events could record energy gain or loss and the total energy of a system is the total of all events/subsystems  associated with the Higgs system. Throw in a timestamp on these events and we have the basis for time travel.
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See https://www.thenakedscientists.com/forum/index.php?topic=75960.msg575784#msg575784 for more information on universal systems.