I use a 2S Lipohow many volts is the battery in it?
Yes, you are right.that works for some of the uhf's like EzUHF but is on the low power side. They call it good for line of sight flight in the manual. you want the uhf on 12v
yes, but youd have to use something like this
http://fpvlongrange.com/fpv-repeater-system/
if all you wanted was head tracking, that port is on the ezuhf to bypass needing a trainer port like that.
having a spotter has no necessary trainer transmitter rule or law, at lest not yet, simply a guy looking at it in the sky eye to eye for when your looking at a monitor or on goggles. That way if something is coming towards you he can warn you and you know what way to walk to pick it up if needed.