The key bindings are saved in /Users//Library/Application Support/Steinberg/Dorico/keycommands_en.json on Mac or C:\Users<yourname>\AppData\Roaming\Steinberg\Dorico\keycommands_en.json on Win, so you could make a back up copy before starting to experiment.
For the other question: I think the issue is not about “resetting the sound system”. You say that sometimes the sounds load correctly and sometimes not. This suggests the following:
- The sound libraries were not installed correctly or only partially.
- Dorico not telling the audio engine to load the correct sounds.
I first would further investigate into point 1. Is it always the same sounds that get loaded / not loaded?
E.g. the piano will always load, but a violin never. Or is it that a piano sometimes loads and sometimes not?
That what you describe could happen if the HSO library didn’t get installed. Because the piano sound comes from the HALion Sonic library, but for the violin sound by default Dorico will choose the HSO library. But if that one isn’t there or can’t be found, then that ‘First Contact’ sound will get loaded.
So I propose, you create a new project with a piano and a violin and tell me what sounds do get loaded.