Dear
I like how you focus on the 'real-world' aspect of information, and I agree with your broad-based, common-sense approach.
My view is that much of the confusion concerning information stems from physicists ignoring the role of the observer in the field of observation. This should not be the case - as you put it: 'We have physics at the level of the particle, and physics at the level of the cosmos, but the bit in the middle where living things reside is also the domain of physics.'
That's well said, and I agree with you that information is subjective experience: The persistent conundrum is to figure out how we can account for 'objective experience' - or facts and truths.
I show in my essay that the objective truth (or, at least, any significantly less subjective truth) only exists for a certain time, and relative to a particular group of evolving observers. The same applies to numbers - they only have significance relative to an observer - and as distant space, quanta, or great speeds become involved, the fundamental nature of numbers - and even law-of-nature equations - changes.
A Bit is not necessarily information - but something that can be perceived. Everything is positive-negative (and derived from the original proton-electron), but whether the observer perceives a Bit-structure, and how he perceives it at a given time and speed, and from a given location, is variable. Ultimately, whatever reading is taken, whatever information is considered as existing, will not be permanent - because what makes the cosmos 'fly' (or 'breathes fire' into things, as you quote Hawking) - is simply the observer's correlation with the inorganic realm of the cosmos.
This correlation is caused and maintained by the same energy-field force that defines a proton and an electron, and makes each separate from the other - therefore creating the original positive-negative charge that initiated the cosmos; it is the 'non-Platonic physical/information structure' that you mention.
This also means, if you agree, that there are other 'categories' besides those you mention - and that these must be the most fundamental: namely, the inorganic, organic, and sensory-cognitive realms that emerge from this correlated system. As you say: 'It seems to be clear that the evolution of complex life requires the evolution of new categories of information, and this in turn requires the construction of new categories interconnected to currently existing reality.'
Given your broad perspective, I'm sure you'll find many points of interest in my essay - as I certainly have in yours: it is a well-written, clear and focused work for which you should be congratulated. I have rated it highly, and wish you all the best in the competition -
John.