A countries sovereignty has exactly zero to do with whether or not the are foreign military bases on their soil...
Germany wants the money the bases bring and likely the perceived protection they present. If they didn't see the latter then the money point is key. How much does the US spend to maintain those bases and do they pay fees beyond that to have them?
As a Libertarian I would be more than happy seeing us out of every country that is peaceful. We have no real need to be there in this day and age with the ease at which power can be projected. I won't go into the question of being in certain other countries because of disagreements which led to war, declared or not.
Each Chancellor has to sign a paper called Kanzlerakte, that he agrees, to give up sovereignty at lot of cases, e.e. intelligence, military.
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.
US barracks are extraterritoriality zones, and US soldiers are not under German jurisdiction.
And better read the 2+4 itself, and not 3rd party writeups like Wikipedia.
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.
Again, please cite your claims.
There were plenty of shenanigans going on between the U.S. and German politicians in the early BRD days. But the scanned document everyone's been passing around purporting to refer to the so-called Kanzlerakte is obviously a fake.