Can Data Route be used to transfer data over the Internet?

Yes, by installing the OAS Service at the data source and the destination the values can be setup to automatically transfer remotely.  At the destination set the Data Source of the Value as Tag and set define the data source tag Value, then in the Target tab defines either a local OPC Item or a local or remote Open Automation Software Tag if using a Driver Interface Tag as a destination.

Can I use Data Route to transfer data from PLC to other PLCs without using OPC?

Yes, the following Driver Interfaces are incorporated directly into Open Automation Software: