issue 1 - the SshException ("connection has been closed by the remote connection end") means that you have actually been disconnected before you even called the sftp.Disconnect method. You can safely ignore this exception in this scenario as it only says you are already in the disconnected state which is what you wanted to achieve nevertheless.
issue 2 - I admit that FileZilla log looks nicer, but Rebex logs are not meant to be used for users of your application directly. We have the logs formatted in such a way that helps Rebex components developers and developer that are using Rebex, to identify issues with using our components. The logs are quite low-level, however you can change the verbosity of the logs. Setting the verbosity to
LogLevel.Info would make the logs least verbose.
If you need only a high-level log for users of your app that internally uses Rebex SFTP, you probably need to write a custom log writer or write your custom messages into the Rebex.FileLogWriter via one of the Write methods.