I'd love to hear how this framework would describe processes underlying reactions in a specific situation

First of all, a caveat. This is a much smaller field than the rest of Psychology and there are a lot of areas that haven't been addressed. So my answer to a lot of questions will be "we don't have a story yet". I think we in Psychology need to be more willing to admit our own ignorance. Theoretical perspectives that make it too easy to come up with an explanation for novel situations are a little concerning as well (think Freud---and I would argue computationalism as the same problem). It shouldn't be easy to answer these questions.

I tell you, the subject in the experiment, that you'll see a blue and red light, and that the red light will precede a shock. and you show immediate conditioned responding (heart rate spike, etc) to the red light, even without ever receiving the shock.

how would this model explain such a process (or, more importantly, how would it differ from a conventional cognitive computational framework)?

This one isn't too hard, though (ha! I'm falling into my own trap). After all, conditioning is a behavioral paradigm and the behaviorists were not cognitivists or computationalists. In fact, ecological psychologists are sometimes derided as neo-behaviorists. While this doesn't do justice to our theoretical perspective, it is true that we share more with the behaviorists than cognitivists do. The upshot is that conditioning s a psychological phenomenon for which a computational explanation is not seen as logically necessary, as many are.

I suppose the issue is, then, how linguistic information can bring a person into a state as if they had been conditioned. This requires an ecological account of linguistic information, which is a challenging area for us to be sure (after all, language is itself symbolic and the challenges that brings were at the root of the cognitive revolution in the first place). Andrew Wilson, who was interviewed in the linked post, has made some stabs in this direction recently. Tony Chemero, in his book (linked in the post) and elsewhere has argued for a re-characterization of ecological information that allows for information arising from constraints that hold by convention as well as constraints that hold by natural law (as in the traditional ecological understanding of information that works so well for perception and action). I think this perspective is taking hold in ecological psychology, although we haven't yet seen anyone take off with it and develop an experiment, ecological psycholinguistics.

The story, then, is that the participant picks up linguistic information about a constraint between properties of the environment (the light and the shock). The participant therefore experiences the red light as carrying information about an upcoming shock. Perceiving the red light is thereafter also perceiving that a shock is imminent.

My guess is that from a computational perspective, this experiment hinges on how a participant's symbolic beliefs arising as a result of the instruction can "leak" into the presumably "lower-level" (perhaps non-symbolic?) system that underlies conditioning.

From an ecological perspective, the experiment hinges on drawing a parallel between how constraints between environmental events are perceived directly and how they are perceived indirectly, through language. Ecological psychologists, believing in direct perception, are reluctant to do so but it seem to me this is a more pedestrian form of indirectness than the kind involved in the conventional claim that all perception is necessarily indirect.

I recognize that that was a bit of a non-answer (it would be too good to be true if I had a complete answer) but hopefully it gives you some idea of the perspective. At least, the questions that experiment would prompt, if not the answers.

a second question, if you're up for it: how does this model account for individual differences in what we might broadly call personality?

I'm not sure, but from my experience cognitive theorists aren't that interested in personality either. I haven't read much personality psychology but I can't imagine they are as committed to the computational metaphors as, say, perception researchers or memory researchers are.

They probably use words like "representation" without realizing the ontological baggage they bring, but I can't imagine that leading theories of personality rely heavily on computationalism. Meaning that they may not need much revision to be palatable to an ecological perspective. But I could be wrong; I clearly don't know much about personality psychology.