Perhaps I should have read between the lines better and instead of telling you what I see (which is what the title of your post asked for), told you what I think might be going on.
I know how the spot function works, but thanks for that bit of clarification. Knowing what the temperatures of the areas near them would have been nice, but no more conclusive in any case, so never mind.
As you allude to in your post, cooler areas could be caused by any number of things including moisture, air leakage, and bad insulation. So, the logical approach would be to employ a process of elimination.
Taking them one at a time:
Moisture - Since we have no moisture meter readings to help us (correct?), we are left to look for visual clues like discoloration. In the first pair of photos, it is impossible to tell whether there is any due to uneven lighting. In the second set, there appears to be some slight discoloration, but it is not consistent with other moisture stains I have seen, and is well above the coolest area in the IR photo. In the third set, I see no discoloration. In the fourth set, I can see a slightly cooler area that coincides with the ceiling repair, but it’s pretty amorphous. I would say of all of the images, that one would be least likely to be associated with moisture, but that is just a guess.
Air leakage - With the first two sets of photos, we cannot eliminate air leakage, because either the areas behind these walls were inaccessible thus un-inspected, or they were inspected and that information is being withheld to test our deductive reasoning capabilities. In the third and fourth sets, these areas are not near exterior walls, and I see no trail leading to them, so I’m thinking not.
Bad insulation - It’s a very sad thing when Good Insulation goes Bad, thus tempting to lay blame at its door (or wall or ceiling or whatever). However, of the three suspects, this is the least likely. Thermal patterns I have seen from missing or sparse insulation tend to run joist-to-joist or stud-to-stud, giving sharp, straight-edged patterns where the structural members are and less-well-defined edges between them. Not seeing that here. Space between first and second floors are not typically insulated, so unlikely to be the culprit in the third and fourth sets of photos.
Moisture - Possible (given the information provided) in all three locations depicted.
Air Leakage - Possible in the first two locations. If you put a gun to my head and said “guess”, this is what I would guess, but not so much in the third location. That would be “Moisture”
Bad Insulation - Possible in the first two locations, but not as likely as our other choices, and highly unlikely in the third location since there would be no insulation there to go bad.
It will be interesting to see what others have to say.