33y.o. academic seeking permanent lease in Berlin starting May 1, 2020

I am an academic linguist from the US who moved to Germany after receiving my PhD at Harvard. After teaching and doing research at two different German universities, I am taking a break to study the language, finish research projects, and volunteer. I'm looking for a permanent lease for a 2+-Zimmer apartment on a quiet street, with or without a kitchen, furnished or unfurnished. I pay rent not with paychecks/wages but with income from invested capital, and can pay up to two years' rent in advance if the apartment is a good match. I can provide proof of assets along with past income statements and future distribution accounting. I can also provide several years of positive landlord references. I am a B2 German speaker improving quickly with a bilingual partner who translates for me. (My partner lives in Berlin but we do not live together; I will occupy the apartment alone.)

I am interested in properties that are well-connected to public transit, are situated relatively quietly (loud neighbors don't bother me, a busy intersection a few blocks away is okay, but I prefer my building/block be calm), offer privacy (I prefer to live alone, and have the lease in my name only, but would be willing to compromise for e.g. a room in a WG that has its own bathroom), and are functional spaces with character that have been lived in with care. Aside from these, I am very flexible.

+++***At the moment, due to CoViD-19 disruptions, I am also interested in temporary sublets (Untervermietungen) which could house me for a few months until it becomes easier to begin a long-term housing search.***+++

More about me:
I'm a 33-yo woman originally from Michigan, in the midwestern US (which has a reputation for producing gentle, friendly citizens). I am a professional academic and nonprofessional creative, and I enjoy writing music (guitar, piano, singing), performing (collaborative performance art), labor organizing and political activism, traveling, dance, bodywork, world- and people-exploration, community-building. I'm a detail-oriented and conscientious person who pays special attention to the various things that keep a home running smoothly: regular cleaning, repairs and maintenance, good communication with building managers/staff, interior design (one of my favorite hobbies), and good relations with neighbors. I always pay my rent/bills in full, and on time, and address problems promptly, including healthy and regular communication with co-interested parties like the landlord & building staff.