My pains hurt. My food tastes. Voices and music sound like something.

Um, those are all tautologies, so I'm not sure how to respond. If we define "qualia" as "what it feels like to have a feeling", then, well - that's just a feeling, right? And "qualia" is just a redundant and pretentious word, whose only intelligible purpose is to make a mystery of something that is relatively well understood (e.g: the "hard problem of consciousness"). No?

Erm, sorry for the snark, but seriously: has talk of qualia, as distinct from mere perceptions, ever achieved any useful or even interesting results? Consciousness will continue to be a mystery to people as long as they refuse to accept any answers - as long as they say: "Okay, you've explained everything worth knowing about how I, as an information processing system, perceive and respond to my environment. And you've explained everything worth knowing about how I perceive my own perceptions of my environment, and perceive those perceptions, and so on ad infinitum - but you still haven't explained why it feels like something to have those perceptions."

Do you go drink the wine or just read the label? Do you go on holiday or just read the brochure?

Ha! That's actually not far off. But it's because I'm a total nerd who tries to eat healthy and avoid unnecessary expenses - not because of how I feel about qualia. I think that happiness should be a consequence of good things happening, not that happiness is a good thing in itself. So I try to avoid doing things (like drugs) that would decouple my feelings from outcomes in the real world. In fact, if I just did whatever I felt like at any given time, I would end up even less outgoing - less adventurous.

I don't think a program has to be very sophisticated to feel pain. But it does have to exhibit some kind of learning. For example:

.def wanderer (locations, utility, X):
..while True:
.
...for some random l1, l2 in locations:
....if utility[l1] < utility[l2]:
.....my_location = l2
....else:
.....my_location = l1
.
...if X(my_location, current_time):
....utility[my_location] = utility[my_location] - 1
.
...current_time = current_time + 1

This program aimlessly wanders over a space of locations, but eventually tends to avoid locations where X has returned True at past times. It seems obvious to me that X is pain, and that this program experiences pain. You might say that the program experiences less pain than we do, because the pain response is so simple. Or you might argue that it experiences pain more intensely, because all it does is implement the pain response. Either position seems valid, but again it's all academic to me, because I don't believe pain or pleasure are good or bad things in themselves.

To answer your question, a thermostat that is blocked from changing the temperature is frustrated, not necessarily in pain. Although, changing the setting on a working thermostat may be pain, because it is a stimulus that causes a change in the persistent behavior a system, directing it to extricate itself from its current situation.

(edit: had trouble with indentation.)