But are you sure they
can buy it off steam then?
3. and 4. are toughies, but if you are really determined to get the game out on the German market you might have to get rid of something
. Chainsaws and flamethrowers are pretty iffy, dismemberment is also a topic for itself especially seeing that your enemies are so similar to humans.
You can either not try at all or you can make a fool out of yourself for getting rid of the harsh stuff and replacing it with something uncool. Specimen -> robots. Greyed out skins, red eyes and screws for gibs. Has been done before, got a moderate outcry from fans and that was it.
Another option you could do (pretty much amounts to falling back to passive aggressiveness on your part...) is to make replacements for everything that is deemed too violent in this game but make the replacements so ridiculous that it has to come across as a message. That way you don't come across as pussies that cower before the USK but as disgruntled heroes that make a stand against it. Might get some publicity just for that too!
Like making the flamethrower a cream squirter with colorful pieces of candy in the cream and replace every woshing fire-sound from it with something really squishy. No new reloading animation needed. Just make the character lower the empty weapon off-screen and have it come back up full.
Replace the chainsaw with a device that has a rotating hand with a white glove on it (like robotic machines had in old Mickey Mouse type cartoons) that can be used to turbo-slap enemies. Blood drawn from this type of attack would be colored light grey to make it look like enemies are just being dusted off.
Blown off limbs don't get blown off but get the cartoony "insta-bandage" treatment. Gameplay would be identical but it would look wacky as heck.
An eventual crowbar could become a Mary Poppins crane with a talking bird-thing on the handle that makes wacky sounds when you hit somebody with it and makes ouch-sounds when you hit solid objects.
The obvious solution for knifes would be to make them colored permanent markers and slash-wounds could look like naughty words that are written on the enemies (not too naughty though...
).
If you have an option for full and reduced gore in the international versions you can add an additional option for wacky gore to that list which makes the game look like the German version. Kind of like the "Hippie blood" with flowers for blood and fruits for gibs in Serious Sam. It should get a laugh out of players so it wouldn't be a complete waste of time. Who knows, some people might even like it.
If your specimen blink, make your dead specimen blink too. That way they aren't killed but just dispatched...
It's a lot of work, but it might pay off with the increased publicity and because some people might buy it just to support the message against the USK if you point out that angle a bit in your marketing.