Walk out the door and don’t go back into the dealer until you know what the numbers should be and you have a dealer that’s agreed to the deal. You really don’t want to be trying to work these details out in real time at the dealer.
The difference in RV could be due to them running the numbers for a different amount of annual miles vs what edmunds showed, or you getting the numbers from edmunds for 36 months instead of 39, etc.
Beyond that, it looks like they’re selling it to you for almost full MSRP. What is VW partner program supposed to be?