To my original post - I figured out the issue with video chatting on my tablet.
Turns out it was the protective case I had on the tablet. I was using the Poetic Revolution (ruggedized) case - and as soon as I took it off, the video chat audio started working like it should. I suspect the case was either compressing the tablet too much in the mic/speaker area (resulting in the choppy input and output) or otherwise blocking/deflecting the sound in the mic/speaker region. Maybe it's an issue with the tablet - loose connection inside - but in any case it's working fine without the case.
I'm a little disappointed in Poetic - I've not gotten anything but a "we received your email" response since I inquired about this issue. Definitely not the same level of customer service you'd get from Otterbox, but sadly the don't make a case for the N10.