Learn English – What’s the meaning of “out of being an ass”

High standard, upmarket professional - or at least presenting themself as high standard, it's slightly derogatory.

eg. "He had a fancy-ass lawyer" = "he had an expensive, up market looking lawyer"

Back in the days when ovens were often powered by gas with no added chemicals to make it smell bad, a purported method of suicide was to stick your head in the oven and turn on the gas without lighting it (the modern equivalent would be running your car in a closed garage). While that was quite a while ago now, I can't think of any other meaning this phrase could have.

Exactly what this translates to in terms of how well John is doing depends on his personality. If John is the sort to joke about committing suicide, I would probably take the meaning as: things aren't as bad as they could be, but they're not very good, either. If John seems like the type of person who wouldn't joke about committing suicide, you might want to take this much more seriously.