Attached is a sample profile that goes along with the new beta (v1.6.1.2) that contains some commands that demonstrate using the 'Set Audio Level' action. As I write this, I am realizing that the commands are heavily using dynamic commands and tokens to get things done. If it's not clear what is going on, just message here.
Note: Sometimes Spotify will not respond properly. The System Volume Mixer is moving, but Spotify just wont have it ;) I am not sure what's going on, but a reboot seemed to put things back in order. Not even sure if it's a Spotify thing, but the issue only presented itself with Spotify (and not WMP or VLC).