Yes, the first one is from Duplicati itself (there should be more info that just “Server crashed”).
The two others are Windows crash log handling and not valuable unless you are using some of Microsofts crash dump viewers.
Sure, it should just exit with an error code, no need to re-throw the exception after it has been reported. But it is tricky to get right, so we are sure that the error is reported, throwing it ensures that it is reported and the process stops.
That is the sysadmins plight: determine the right level of security. If you use a webservice password, ServerUtil does not need the encryption key.