I think you guys can honest-to-god just make most of it up. If people want a list of interesting locations or photo references, I can do that (although not until I'm back to Beijing).

The modern part of the city is about the same as any modernizing city. Shenzhen is the classic Chinese example, but in the western world, I'd compare to downtown Seattle.

The lakeside part looks like fields/forest (depending on the preference of the land's owner), a few mansions, and a lake at one end. It's essentially the Einzbern manor that was in Fuyuki, except a bit bigger.

Xishi, the tourist trap area, is heavily based off of Jinli Street. I personally would not be offended if people just treated it as the campiest Chinatown that ever was.

The courtyard housing is harder to explain if you're not familiar with it. Conveniently, I just visited my grandparents who are vacationing at such a community, and I took a bunch of photos. As an explanation though, just envision a regular street (Tanz, envision a regular street; everyone else, envision a dirt road that's somehow urban). There's a lot of big buildings, but those buildings are more like suite-style dorms with lots of central outdoor communal space. Like dorms, sometimes there's a really tight community in each courtyard, but sometimes they barely talk to each other. It just depends.