I got nothing on causes of this, but will share that I hate peanut butter. Probably one of the reasons I was kicked out of the US (haha). But, before I had kids, I would get a massive PB craving about once a year. It doesn't happen anymore, but my diet and probably my physiology have changed somewhat with the years. So I agree that there's probably some nutritional thing going on, too.
I concur with you on chocolate milk (blech), BUT dark chocolate is actually good for you (small quantities, of course) for all the reasons you cite above. I've discovered recently that while milk or semi-sweet chocolate makes me ill, dark chocolate doesn't. I'm sure its the extra sugar and fat in them. But the best part is, is plain, I don't really like dark chocolate that much, so when I crave, I eat WAY less.
My guess is it probably is skating related. You've just worked out and your body wants compensation! There are worse things to crave. Like you know, peanut butter!
Or Ben and Jerry's......