You're mostly right :-) BTW, about the hand -- our body is made of mostly water, so if your hand is covering the SD slot, yes, it will have an impact on the range. Your body, on the other hand, while the camera is hanging around your neck -- should have less of an impact, with a good N router that has MIMO. Thanks to MIMO, the signals can bend around obstacles.I think for me, speed is not that much of an issue, but range. Need to go source for a router with high-gain good antenna say 9dBi (high-power not that much of an issue, as Eye Fi is not high-power, so the router might be able to "shout very loudly" but since its deaf also wakalimasen unless Eye Fi also can shout very loudly, which it cannot).
At most I use 12V battery power and carry the router with me lah.... The Buffalo router which I am using is 12V direct.
One tip for you, if you want to extend your range -- put a small pocket router on your belt, and then use WDS to bridge the router that's on you, to your main router. For more details, read about it in our forums, and research WDS online: