I am also a young male, 22 now. Three years ago I guess I had similar problems. That you know about his mental health stuff is a great indication that he'll live a while longer. If someone wants to die you won't know anything and then they'll just disappear; found far away from a hospital days later. So I think you are doing great so far (in regards to the suicide threat).
At my second most unstable (most being constant ideation), I would explode into anger at anything even hinting at a lack of self-sufficiency at that age; smashing tables, TV's and putting holes in the walls. I don't know if his anger is similar in that way- that it's triggered when he is reminded that he has nothing of his own; that you can remove his housing, food, clothing and perhaps only meaningful social contact if you wished to. That despite being in the stage of life where your DNA wants you to have moved out and started a family of your own you are completely relying on mommy and daddy for your survival; this takes great maturation and time to accept. It's an extremely volatile situation that all "failed" young men has to deal with nowadays. Some would be better off in prison, where they would at least feel like they have separated themselves from the need for mommy and daddy's care.
To answer the question at hand, I think that you can ease back on the surveillance; but don't blame me if something happens.