1- The $eval and $doEval functions are not deprecated as of Mongo 3.0 Java API () which we use behind the scenes. They are deprecated on the mongoshell and will be deprecated soon in the Java API.
2- If you're planning to execute arbitrary code on your mongodb instance (using eval) you should, from a security perspective, have the full privileges on the database.
3- 4- In the next version of the tMongoDBRow we're moving from eval to command (runCommand) (-). Note that renaming a collection using the command (runCommand) requires access to the admin database.
By the way, the call should succeed on non-secure MongoDB instance. What type of authentication you're using ?
The new changes should be available in Talend 6.1.1. I'll be working on this feature so I'll keep you update on the progress.