Focusing on Find_Extent only for the moment. The error your seeing does appear to be an odd line in the code. I'd suggest using the follow in its place. I'm guessing this is the original code as all your variables match up.
SubMacro Find_Extent
#Date of creation: 9-3-08
#Creates object info for the group and determines the extent.
Create object_info ActiveDoc.firstSelectedElement
ActiveDoc.firstSelectedElement.info.view_context.type = "extent"
Compare_Left = ActiveDoc.firstSelectedElement.info.view_context.rectangle.left
Compare_Right = ActiveDoc.firstSelectedElement.info.view_context.rectangle.right
Compare_Top = ActiveDoc.firstSelectedElement.info.view_context.rectangle.top
Compare_Bottom = ActiveDoc.firstSelectedElement.info.view_context.rectangle.bottom
End SubMacro