I would like to know if netNamedPipeBinding is considered safe:
On one hand NetNamedPipeBinding implements security only on the transport Layer and it uses NTLM (source) that is no longer recommended by Microsoft (source)
On the other hand the Named Pipie is not accessible from a remote computer, and there is no way to eavesdrop on a particular open pipe instance being used to transfer data, or write data to it, unless one can obtain the handle to the specific instance concerned.
This is the reason why I don't know what to think about the security of this solution.