A lot of you responded about my shabbat key problem, and I just wanted to let you know, a regular key is en route! I was meant to have a meeting with the housing officer tonight, and before I could say anything, he said, "all right, yes, well, we've decided to give you a key." I was very relieved and thankful. Although also surprised at the ease with which he about-faced.
On returning home I checked my email and found a response from the Rektor's office-- apparently his secretary had rather a long talk with the housing officer after receiving my plea for help. Mystery solved. And shabbat is going to be much more pleasant than it would have otherwise. Here's to keeping the faith!