And when I went to pick up Twee, she was ensconced on a towel happily nomming away at all of the hay and pellets she could fit into her mouth, so apparently I should not have worried so much.
So:
skin scraping didn't show mites, which (according to the internet) is not reliable as mites are wily critters. She's not itching though, and Nori is completely asymptomatic.
x-rays showed her heart seems a bit better (yay!) though she is a bit gassy. As far as I can tell that is only bad when they are not eating, which is definitely not the problem, and apparently there is a pig massage technique that can help with that.
current non-mammal-expert vet says that bloodwork would require mild anesthesia, which sounds like a bad idea for a pig with a heart condition, and another reason to wait for the usual vet to come back.
she is now hopping on her back legs, which is a symptom of something like arthritis, which is likely in a satin pig especially since we're low around calcium here ever since Nori had bladder stones. though the vet specifically said he didn't see arthritis on her August x-rays.
and i have never seen a pig poop this much, which is saying a lot.
At this point I've diagnosed her with everything so I need to stop. I don't like her weight loss trend in the last couple of weeks, but she's stable enough for me to sleep on it - not sure what I could do about it anyway considering she's eating. We have an appointment with the mammal vet next Saturday so she just needs to be okay until then.
There is something about irregular hair loss that invariably makes an animal look twice as sick as they are. I guess I will have to knit her a toupee.