You can hover the mouse over the point in the middle of the tube (Edge.Vertex2) and read the coordinates from the status bar. Enter these coordinates in the Center properties of the array. In your case it would be sufficient to change the Y value, because Z is zero anyway and Y is in axial direction.
This is normal. Features are not stand alone objects, they show only the final state of the history. It might be easier to understand considering a hole: It is not sensible to consider a hole as standalone object, it makes only sense in the context of the object where it is applied to.