I don't comment on the Kanzlerakte, it's obvious fake.
US barracks are not extraterritoriality zones, please cite your claim.
"US soldiers are not under German jurisdiction", this is only partly true. It's part of the "NATO-Truppenstatut". With Art. 19 Abs. 3 Satz 1 ZA (Zusatzabkommen) the foreign soldiers are part of German jurisdiction.
We have peace now since more than a few decades. It doesn't need a signed peace treaty to have peace in a country.
The 2+4 contract has explicitly stopped the allied control.