Is it allowed in Use Case Diagrams to place the same actor at different places in the Same Use Case Diagram because of overview issues?
I have a lot of Use Cases spread all over the diagram but drawing a line to every Use Case from a single actor that is placed on top of the diagram makes the whole Diagram very very confusing, because a lot of association lines strikethrough some of the Use Cases.
Yes it is allowed, there is no rule saying it is forbidden. However that could indicate a problem concerning your actors/UCs, or of course your diagram is just too complex and you have to divide it in several.