The DS230, DS156 and the checklist are the only things that get sent back from packet 3 correct??

Montreal or Vancouver?

If Vancouver:
- fax back DS-230 Part I
- fax back checklist
- fill out DS-156 and DS-156K online (must get print-outs with the barcode) and bring this with you to the interview

For Montreal its just the checklist and DS-230 that are sent back and the DS-156 , filled out online with barcode, is retained until interview time.

My fiance is trying to tell me that the instructions are saying to send the DS156 as well. I'm trying to tell him he's wrong but he's insisting. If he sends that in too and then just brings another copy to the interview would that be ok? I can't really get it through to him he's way to stubborn.

If the instructions say to send it then send it and yeah , I'd make a backup just in case.