Your numbers are so far off. I have no illusions about this car. It will never be fast. Just trying to make some more power without wasting a ton of money.
Please don't give up on the full K04 setup. I think the idea of having a very fast AWD Tiguan is awesome.
Would some strategic dynamat/fat-mat/similar placement eat up a lot of the added NVH from an intake and DP? I always did it on the cars I put systems in, but I also lined my old Bronco with it because the headers, intake and exhaust were horrible to hear for any sustained period. It's pretty expensive to install if you don't want to do it yourself, and the panels and carpets in a newer Tiguan are a bigger PITA than in an old Bronco if you do do it yourself, but if can definitely turn the car into a tomb.
That said, I have no idea how expensive it would be to have a K04-appropriate DP fabbed if there are none available from the normal makers. But, I'd throw in $20 if you did a kickstarter drive for "Impossibly Cool Tiguan."
Also, it might be useful to convince yourself to look at the stg 1 tune investment as a sunk cost. You can't can't recoup what you paid, so don't factor that into your K04 decision; just think about the relative performance gain from stg 1 to whatever K04 setup you plan to do. I use my economist logic to justify questionable financial decisions in my head all the time. It just never works on my wife, and that's why I still have a K03.