MFT (Managed File Transfer) scenarios are not clearly described by SAP, so please follow this short description to set up a simple MFT scenario:
Polling a source directory/folder via standard FILE/FTP(S)/SFTP adapter, delete or archive the file and write the file(s) to a target directory/folder.
No activities needed/mandatory for SLD or ESR (!).
The Service Interfaces (Outbound/Inbound) can be designed of course, but this is not mandatory for the configuration/runtime.
As the file content is not XML, the modeling of a data type is not obligatory.
However, to apply a proper naming and reuse, it would be recommended to create a Software Component (e.g. MFT 1.0 of whitepaper-id.com) and create Dummy Service Interfaces (e.g. File_Out / File_In in a namespace e.g. urn:whint.de:mft).
In the Integration Directory the routing configuration can be done based on the created Service Interfaces or by using Dummy Interfaces explicitly (iFlow in NWDS) or by manually entering the name of the Service Interface in the Integrated Configuration.
For the sender channel configuration make sure you read the Adapter Specific Message Attributes (ASMA) for the File Name to transport it accordingly as meta data to the target communication channel.
And then you are done, no rocket science here…