Catch-up Blitz: German Achorns and German Bureaucracy

I met Mr. Achorn on my seventh day in Germany. I had finally found my way to the correct office to do the correct bit of paperwork to get the ball rolling on all those wonderful doorways: visas to stay and SOFA status to get on base and mail packages and visit the library and get driving all over Europe. I waited in his lobby for forty minutes, reading posters on the wall about immigration laws and proper procedure, and the dire consequences of misinforming a government employee at any point in the process. If there is anything they take really seriously in Germany, it's beer and bureaucracy. He was polite, even quite friendly and joking with me. He answered all my questions and provided explanations when I was confused. He was new in the office, also just moved to Bad Schwalbach. He clearly marked off which items I needed to obtain to get the process rolling, and included his email address if I had any questions. Lovely!
I got started immediately, stopping on the way home to take my biometric pass photos. That evening, I emailed him my proof of insurance, told my boss how important it was to have my name on the mailbox (they won't deliver if your name isn't on the box), and asked for the 100 euros to cover the fee. Then came the debacle where my boss lost her wallet (it was lying on the counter) and canceled all of her bank and credit cards so that she didn't have access to her money either, but after another 5 days or so I was able to show up with everything I needed. Again, Mr. Achorn was friendly and firm, making clear that I was here at the moment on a Tourist visa, and was allowed to be in Germany for three months on that visa. I was expressly forbidden from working without a permit-- including as an au pair. I was here as a guest until I received the appropriate documents in the mail, which was not guaranteed. It would need to be approved by the appropriate body. (I have no idea if that is a committee or just an official.) It was good that I had a contract, because a contract was needed to give approval for work and work was needed as grounds for the visa to stay.
Five days later, after it had all fallen apart, I emailed Mr. Achorn again. My boss wanted me to try to get the fee back (since when does any bureaucracy refund fees? that's a nice dream.) and I wanted to ask my friendly Mr. Achorn what kind of paperwork I needed to do now that my situation had changed. His first question? "Where are you living? I need to know if I am still responsible for you." Typical. Essentially, when I told him, his main point became that I needed to register in the new location in order for him to no longer be responsible for my file. Except that my generous and hospitable friend's rent might go up if I were registered at her apartment, which is ridiculous to start with since I was only one-month guest. I tried to explain this, stressing over composing emails in German and going back in forth with edits. In the end, I made an intentional decision to ignore this, hoping a little silence, a little holding close of the cards, would be in my favor. We will see, when/ if it comes time for me to complete work permit/visa paperwork if this story with Mr. Achorn has a pleasant ending or foreshadows an unpleasant twist. He was waiting for my file to come from Berlin, from eight years ago, so I know that anything that goes into my file here will be there literally forever, though I may never know the contents.
In the meantime, I am grateful for his thorough explanations. I am prepared: I know how much time I have and I know what kind of paperwork I need to be an au pair. I know I need to bring lots of cash to the Auslaenderbehoerde and I need to keep my biometric pass photos. I know I need to get there first thing when it opens and I know that I do not need to be intimidated by the process: I can follow a checklist, and now I have some practice writing inquisitive emails in German. I just may send Mr. Achorn a thank-you note.