to your first ? i don't think you can do that since the X,Y,Z are the location for each object so when you change one it goes for them all.
to you second ? if you hold the LEFT mouse button down and drag over the object you want you get them inside a green square and they all get marked then you can move them around like if they was one object..
have you tried this MOD for working in 3den http://steamcommunity.com/sharedfiles/filedetails/?id=623475643&searchtext=3den+enhanced
It has some of the features you can use for your fences..