Yea, 400 games is the threshold but thats with the NHLPA pension, NHL itself doesn't give one.
As for the OP - I have heard NHL will pay for things like rehab for former players if they need it. Probably expensive medical procedures too I would guess, or maybe the NHLPA would cover that too.
I don't imagine its terribly hard for former players to latch on with the league or a team for a job, you see all kinds of former players, usually guys who were AHL fodder/occasional NHL call ups, with jobs for the league or its teams.