9) tend to yawn a lot even when I've had tons of sleep -- this goes along with the lethargy -- still though I've been very lethargic in the past without feeling so miserable and weak
This might be due to obstructive or central sleep apnea. You would be surprised by how many people have sleep apnea and don't know it. I have seen patients who have been tired and lethargic for years and after having a sleep study done and after wearing a BiPAP or CPAP machine for a few nights come back and say they feel like they have been reborn. This doesn't explain most of the symptoms posted but could make your friend feel a hell of a lot better if this is diagnosed and treated.