The sex thing is a big problem.
In the past, great artists were able to find companionship and sex despite poverty and oddness. Why is it that hackers have such difficulty? If Richard Stallman's medium was anything other than computers he would have to fight off the women, but somehow hackers are girl-repellent despite being devoted artistic geniuses?
I don't think his devotion will last long or stay fresh unless he starts fulfilling sex and romance needs. Exposure like this NYT article should help, and also a rising income would help a lot. Then he still has to make time for women and he might find the intimacy too threatening.
Anyway for the sake of Dwarf Fortress and his art ambitions I hope he figures out a way to fulfill sex needs. Other than that I don't see anything unsustainable or obviously unhealthy about his lifestyle.