PRPC_SOAPOper is used by the SOAP APIs that enable PMF or other external systems to integrate with the development system. If you aren't using those, or you've updated the SOAP Authentication Profile used by them with a custom operator, it is safe to delete.
Not used. This operator ID is locked, except for the password. Change the password from the Profile display. This Operator ID is overwritten during an upgrade; any changes you made before the upgrade are lost.
Batch@pega.com was used in older versions of PRPC and this is kept in the system for backward compatibility in order to support upgrade processes from 6.x to 7.x versions.