1) Not a correct solution. A citation should not contain a date this is a job for the source and it has a date. It is possible that AMT is missusing the term citation in that it is asking for all of the information used in a "written citation". If they are then no changes are needed just a better translation of data from AMT to FTM.
2) Not a correct solution either. A publication date for a written citation is needed, the request for the data is just in a different place than FTM. Again, a better translation of data from AMT to FTM is needed.
3) No not correct either. Citation Detail is not where the data should end up. This is now a field in the Source Publication Date field.
Structure does not matter. Use does. If the data ends up being used the same way who cares how it is entered and stored.