Hello, in many cases the city mark guaranteed a certain minimal fineness, most often 12 Lot. So it simply was not necessary to punch the fineness. It would have been legal, but it was superfluous and so it usually was not done. Mostly it was done if the fineness actually used was higher than necessary. Take Berlin: the bear would guarantee 12 Lot, but sometimes for higher nobility or for the imperial court a higher fineness was used, up to 15 Lot. In those cases the makers also punched the higher fineness.
Ad point 2: it is a common misunderstanding that current German hallmarking regulations are mandatory. They are NOT, they are what lawyers call facultative (optional). It was legal to sell gold or silver objects in Germany with an incomplete set of marks or without any marks at all. But this would create a kind of credibility problem for the seller: would a client believe that this really was gold or silver a stated ? So it was simply smarter to follow the regulations and punch the piece correctly. And IF the piece was marked, THEN regulations would have to be followd. As to the loopholes of the regulations and the relevance for dealing with Hanau pseudo marks see here
https://www.925-1000.com/Fgerman_hanau.htmlRegards Bahner