1) Not at the moment. Replication must be performed by the application. If your model uses an authoritative server where all generation and edition happens, you can take a look at the ThinClient example in the SDK. This is not using UE, but it shows how clients can receive content from the server. In general, you would replace the local procedural and edition layers in the client by the remote voxel layer shown in the thin client example.
2) See answer above.
3) Yes, if your server is fully authoritative, you can send a message to the clients every time a cell is modified. The client in response would request these cells to be updated by calling processModifiedCells() into the clipmapview object:
changedCells.insert(modifiedCells); // modifiedCells is a set of cells that changed from the server and are relevant to the client
TMap<CellId, CCellData::CInstanceEditionVolume> volumes;
clipmapView.processModifiedCells(changedCells, false, &volumes);