The new character Cylindric the German is a very polite and sympathetic character. This was a decision made by Albert Uderzo who regretted the book "Asterix and the Goths" where all the Germans Asterix met were incredibly aggressive, warlike and far from friendly.
Unlike the other Asterix movies this one isn't based upon any of the Asterix books but is a completely original story written by Asterix creators Albert Uderzo and René Goscinny.
In Germany the search for permit A38 became a catchphrase to describe overburdened bureaucracy.
"The Place That Sends You Mad" is not all that anachronistic. The Roman empire, especially its later eastern part (Byzantium) was famous for its over-complicated and heavy bureaucracy. All that red tape was partly responsible for the empire's fall.
At one point a chicken lays some bizarre looking eggs. One is in the shape of Donald Duck's head. Note that the scene was cut in some versions due to copyright problems.