There is no way to have a live update happening between servers. The
custom code would be interesting to say the least. What happens if
someone in location 1 makes a change  to doc1 and someone from location
is making changes to doc1 location 2? Who wins? Or will there be code to
deal with the merge?

The only thing that is close to this is that you create a readonly
version from location1 and set it up in location 2. You can backup
server1 and restore it as a readonly on another server  in another
location. This still requires that if a user wants to edit a document,
they must connect  to the server that has the editable copy.

I am interested in why the client  does not have 2 servers  located in 2
locations, each indexing the other as a content source. This way a
search on one server will show docs matching on the second server.