Sleep issues: fibro can be without, but sleep issues can be independent of pain.
Just to be clear, not everyone with fibromyalgia has insomnia or sleep issues, although it is common for people to have trouble sleeping because of physical pain. However, to say that "the two key issues" are those two things is not fully accurate.
Not everyone has sleep issues, so it's not one of "the two" key issues for everyone, I agree - at least if by 'key' we mean it's a prerequisite/'necessary'.
But just to get that "aside" even clearer:
It's one of the 6 possible main symptoms additionally to pain, of which we have to have quite a few to "score".
But it's in the first 3 = fatigue, waking unrefreshed, cognitive symptoms (= 'fog'),
which can weigh up to 3x as much as the 2nd 3 = headaches, pain or cramps in abdomen (= 'IBS') or depression.
So it's often a major issue, even tho it's not 'have to have'.
So we can still ask and think about further symptoms other than pain, otherwise it might be CPRS.
According to the criteria we do "need" at least 5 points on the "severe symptoms", pain isn't ("usually") enough - we can still get diagnosed for individual reasons of course, the criteria aren't cut in stone, they aim at being pragmatic for not leaving anyone out, but not putting anyone in that will likely have something else.
However fibro can come with more than enough sleep issues that are precisely
not only caused by physical pain, they are often independent and "inexplicable", as in my case.
Me: I could always sleep well before fibro, whenever I wanted to, even despite pain. The insomnia started with my full flare.
Sleep was one of the first things I worked on partly successfully not only by getting my pains better under control, but tons of other things.
Then I got all my pains under control, so waking up was hardly ever due to pain / discomfort, but I was still up 1-3h per night despite having to prevent 30 triggers and to take 12 sleep supps that helped a little.
My sleep lab psychiatrist guessed it might be a combination of several known sleep disorders that were singly too slight to be detected by him. Not even his suggestion of levodopa to see if part of it was RLS worked, however.
What now works excellently for my sleep is trigger prevention, most of the supps, "blue" "daylight" only in the morning (etc.) and LD N. If I forget one of these that can cost me one to several hours of sleep, despite no pain to mention.