A:AnswerPhysically, you can of course mount it anywhere you like, but it certainly isn't designed for "outdoor" use even when not directly exposed to rain.
A:AnswerPower, yes. Up Down can do three things. 4th button is CH/INPUT: "Press to select volume, channel, or input mode, then press/+ or /– to adjust the volume, change the channel, or select the video input source."
A:AnswerI am using the stand that came with the TV. It is 1 1/8 inches from the bottom of the frame to the shelf the TV is sitting on. My Citrix box for U-verse sits on the same shelf behind the TV and is able to receive the IR signal from the remote control in the opening under the TV.
A:AnswerAbsolutely. We have our Roku connected to the HDMI port. You could also connect a Blue Ray player to it that streams Netflix as well. Lots of options for streaming, your Roku should work fine.