No support? This "support" page is fucking amazing brilliant everyone brilliant
First of all, OBS has no official support.
Everyone here is a volunteer, and we all do our best to help out those who do need help.
Second, does only game audio skip or voice audio as well.
In your log the Astro mixamp timestamp was behind quite a bit.
Try this:
Plug the Game Capture HD as FAR AWAY as possible from any other USB source.
So if you plug it into the back of your PC, plug it into a USB 2.0 slot, and make sure nothing is connected to the slot next to it.
Next, move all webcams, mice, keyboards as far away as possible and to front USB ports.
Let me know if this helps. Also, please post another log should you do a test stream.