Dear Fredric,
Your concept is very interesting--to consider functions that behave very differently in different domains, as an approach to the 'analog' and 'digital'.
I cannot comment on your mathematical proposal, but my eye was caught by this passage:
'True randomness requires that there be no relationship between one event and
the next event. Pseudorandomness, however, simply implies that we have not
(yet) been able to establish the cause-effect relationship of one event to the
next. For example, "random" numbers that are generated by computer
algorithms are actually pseudorandom rather than random.'
However, we are never in a position to establish absolutely that a pattern is 'truly' random. Secondly, we can only absolutely know that a pattern is pseudo-random if the generating algorithm is already known, which seems to beg the question.
If I understand correctly, your intent is to find the kind of function you describe, which gives a deterministic appearance in one range and a random appearance in another range, in order to find an ultimately deterministic basis for quantum (and/or other apparently chaotic) events? In other words, to show how quantum randomness is actually pseudo-random? I guess the important question is whether such an approach could actually match the results of the current quantum theory.
Best wishes and good luck,
Dan