RE #3
Maybe the problem is with Amazon VOD?
Does your TV have the most current firmware installed?
Have you double checked that your TV is connected at 100TX? (check the lights on the router for that port)
On the small home units it's really more of first in, first served than a priority based on connection type. There are a few that you can program to give priority to (mostly units with phone built in - ie: Vonage, et. al., or ones with 3rd party firmware like DD-WRT), but even if you have one of these units, unless you programmed it, it should operate at the defaults of everything is unrestricted/unlimited (no data speed cap). Wired does usually operate at a higher speed than wireless and is less prone to re-transmits due to less interferrence.