I could be way off, but this is what I saw:
1. VV represents Germany. She is the Germany that was seduced by Goebbels's propaganda machine. She has become dependent on it.
2. Dr. Katz's clinic represents the corruption that continued in German government and society after the war. It became VV's new false god.
3. The Afro-American soldier represents a recurring theme in BRDT: the irony of Nazi Germany's effort to get rid of all "inferior" races, then being occupied and controlled by the ever-present non-Aryan.
4. The sports reporter represents a visitor from modern society who naively thinks he can change everything for the better just by taking an active interest. How easily he is seduced. What does a sports reporter know about such things, anyway?
5. The old couple were the Jews who had fallen victim to Nazi Germany. They were not addicts. They acted as signposts.
It seems to me that Fassbinder is always angry about what Germany (the BRD (Bundesrepublik Deutschland (Federal Republic of Germany))) had become and how it had deteriorated. It became addicted to false ideals, it suffered tremendous guilt, it tried to forge ahead without feeling sorry for itself and without dwelling in the past, and it prostituted itself and continued to act against its ideals so that it might rebuild and eventually pay its debts and maybe even get ahead of a place it had not been since before WWI. As it struggled to keep its head up, it poisoned the minds of its citizens with its continued hypocrisy, and perpetuated the deterioration it tried to alleviate.