luv2cruise99

It can depend on weather. When we did the Labadee zip line, it was rather windy, so everyone had to sit straight up to prevent overspeed.

I've done it, no you don't have to lay back.  Unless they changed the way they do things.  When we went it was one and done.  Not really impressed by it since we have zip lined in several locations.  We did it once and doubt we'll do it again.

Not done it, wife has and my son and I watched a bunch of people waiting for her.
 
My understanding is that the reclined position is recommended to ensure you pick up enough speed to make it to the end but it doesn't have to be a "full" recline, my wife was able to us her camera coming down and got some pics/video.