I am planning to have a work project with multiple file geodatabases, fgdb (consisting of images, grids, feature class, etc) and these will be passed along to three regional offices and will sit on their individual file servers (all servers are linked via distributor file system). And I was told that I can set them up to sync up during the after office hours.

There will be a "parent" fgdb which is sitting in my office and the rest are "child" databases. Of course, this will bring more complex questions, but allow me to ask below questions first. 

1. Do I need any add-on to do it?
2. If no, where do I set this up?
3. Will Symantec back up which run at night be affected or affecting this sync?
4. Is there a way to bring non-ESRI files into fgdb ? (eg. .xls, .dat etc)

FYI. All users, are on 9.3.1 , with ArcMap only, without other ESRI products.