My policy in general is to have as few moving parts as possible. The few inter-dependant projects, the simpler the software, the more straightforward the setup is the easier everything becomes.
PulseAudio is a steaming pile of shit which I've never had working correctly. Even finding basic documentation on how to use it isn't out there.
- play with
pavucontrolas the default user. The wrong sound device may be being used by default, or applications may be configured to use the wrong device, or stuff might be muted, etc.
- play with AlsaMixer. Ensure stuff isn't muted, and the volume is turned up.
gstreamer-related stuff may need to be installed.. I'm not certain.