I've got a Sanyo HD2000A, and the stock battery is rated at 135 minutes, and that's close to what I am seeing in terms of charge life. I also have a third-party battery that is supposed to have a higher capacity, but it doesn't seem to last as long as the Sanyo battery.
The HD2000A has a tiny stereo mic input. It comes with an adapter cable that allows connection a mini, 3.5mm stereo plug.
In regards to hand fatigue, I hadn't noticed any problem, but I never hand-held it for very long. The camera is very light-weight, so it really needs some weight attached to stabilize it. I usually just hand-hold the camera attached to the tripod (with the legs collapsed and folded). The camera's built-in digital image stabilization is not that great.
By the way, I am
selling my HD2000A along with some accessories.