Hello fvefa,
You don't need to do any of this after changing something in a playlist.
The "update" button under "Settings > Mount Points" should only be used when you actually make some changes in the station's configuration (this doesn't include changes to playlists).
The restart button on the left menu, is only used when a restart of the station is required, for example, when you add a DJ account, or change something important under "Settings", like the name of the station.