for wind waker , your can't hear sound because the plugin don't support it.
I don't know exactly what antigap is , but with my computer when i use antigap , i have sound and without , the emulator freeze.
If the game's music format is supported (And is a certain type, I think. It doesn't work with everything.) "Anti-Gap" will play the music without syncing it with the video. Donkey Konga plays fine with this.
it's just because it's less stable with the anti-gap so might crash more than usual. It is usually to fix music that will loop at the start all the time (like Donkey Konga musics). It won't damage anything.
Yeah it's just a little hack that makes sound work even though it shouldn't due to the low speed
Unfortunately it causes a timing problem that has a small chance to cause Dolphin to crash every time you pause and resume the emulator. It's not really dangerous, just to your running dolphin session