When importing issues, many of the issue fields can be mapped to the columns of the source CSV file. However, all imported issues are "authored" by the current user and are created with the current time stamp.
This is not usefull in case of importing issues (e.g. from another data source) created earlier and from different users.

I wish, in the import fields form, there was an additional Author field that behaves similar to the Assignee field. It should allow for mapping a CSV column to the Author field or select one of the visible Redmine user or <> for this purpose.
Similarly, for the creation timestamp (date+time) there should be an opportunity to map it to a column in the CSV-file.