Replication is physically pressing a discs while duplication is burning discs. The difference is the amount of reflectivity in the pits and lands.
The discs you will be making are 720×480 16×9 anamorphic. They will need to be encoded with the 16×9 flag set as well.
When you deliver to a replicator, you will need to supply DDP image files. See the manual on how to export these out of Encore.
The AUDIO_TS is basically useless. Its was intended for the DVD-AUDIO format which fizzled out years ago.