On the porn in Germany issue: Porn is basically treated like films on the "index", meaning it can be only sold and rented in "adult's only" stores.
But you're right: There's very little censorship regarding porn- at least upfront- because it simply gets released "unrated". But- believe it or not- even though the German censors are very liberal with sexual content, they also ban what they regard as "extreme porn" every now and then....but we're talking about stuff that wouldn't stand a second's chance with the BBFC to begin with.
The highest rating in most Scandinavian countries is "15"
!!!!!
Finland is the only exception I know. They still have their "18"....and to be honest, buying a Fulci or "Cannibal Holocaust" with a "15" would feel somewhat less of a treat...at least for me.
On the "More Gore for the Germans" issue: Yes, that was actually true in the golden age of exploitation movies. For instance: The whole part with the zombies in the hospital in "The Beyond" was added to attract the German buyers, because "zombies" were "hip in Germany" back in the early 80's! That feels SOOOOO surreal from a 21.st century point of view....