"Twistoffate", it's been a while since you first posted regarding the concerns you have for your brother, but I just wanted to chip in a little here.
It sounds like he has a whole lot on his plate right now, and it's likely that balding isn't his biggest concern, but it can really tear at you if you let it. My only real advice would be to not make a big deal out of it on your end. I'm certainly not accusing you of it, just pointing out that sometimes people wish to help out the ones they care about but only throw water onto a grease fire (it doesn't actually help...but makes it worse).
As an example: I am overweight and I know it. Sometimes I am a little more sensitive about it than at other times. It NEVER helps when people joke about my weight or insult me, but sometimes people try to act like I'm NOT big. It actually makes me feel worse about it, believe it or not. I know it doesn't directly relate...but the basic point in my whole post is that you should continue to treat your brother with love. Don't lie or baby him...he's a man. A man going through a whole lot, but he'll work it out. He's apparently got some great family! If his friends are half as good, he's in an even better place.
I hope your brother finds his groove.