Jesus no! You don’t deal with mental health patients this way! You should have started a dialogue and keep him occupied until he calms down and possibly comes out himself. And if he doesn’t you break down the door, step back and reevaluate the situation. Not just barge in and shoot him.
Spotifyd is a Spotify daemon, not an user application. It makes perfect sense to run as a service. Though personally I would run it as a user service instead of a system service.