If you export with Kind=Original you retain your Created date, Modified date, Latitude and Longitude. You lose all edits and a Description field.
That's what the Original means. No added metadata, no edits.
If you export with Kind=jpeg the Created and Modified dates are set to the export date, you lose the location data, but you retain a Description field.
The Created and Modified dates are correct for that file. There are two kinds of metadata involved when you consider jpeg or other image file.
One is the file data. This is what the Finder shows. This tells you nothing about the contents of the file, just the File itself.
The problem with File metadata is that it can easily change as the file is moved from place to place or exported, e-mailed, uploaded etc.
Photographs have also got both Exif and IPTC metadata. The date and time that your camera snapped the Photograph is recorded in the Exif metadata. Regardless if what the file date says, this is the actual time recorded by the camera.
Photo applications like iPhoto, Aperture, Lightroom, Picasa, Photoshop etc get their date and time from the Exif metadata.
When you export from iPhoto to the Finder new file is created containing your Photo (and its Exif). The File date is - quite accurately - reported as the date of Export.
However, the Photo Date doesn't change.
The problem is that the Finder doesn't work with Exif.
So, your photo has the correct date, and so does the file, but they are different things. To sort on the Photo date you'll need to use a photo app.
Also you don't lose any metadata - including the location material - if you choose the correct export settings
This User Tip
https://discussions.apple.com/docs/DOC-4921
has details of the options in the Export dialogue.
You can check this by taking one picture and export it both ways to your desktop and check the Get Info fields.
The Get Info facility in the Finder refers only to File Metadata and not to the Photo metadata at all.