I agree that the CoX base editor was pretty broken, and also the comment about the furniture being janky. Another problem, at least before issue 7 or 8 (can't remember which) was the insanely high cost of everything group-related. Even the rent was nearly impossible to afford for a small group. I agree with the idea of having smaller footprints for core functions as well as having a neutral aesthetic option.
I always wanted the ability to add environmental effects, like water features and fog. Having 3D placement out of the box is a must, without the need for a physical anchor. Also, flooring with a depth dimension; it was possible to emulate multi-story rooms in CoX using floor panels that had zero height, which looked odd. An option for an outdoor setting would be really, really cool, or better yet a mix of indoor and outdoor. (Same goes for underground, underwater, airborne, etc.)
It would be really great to have multiple save states (almost like an emulator), so you can prototype a couple of different things without a bunch of rework. This might be stupid, but I'd personally rather have something more like a wire frame option, so I can design by actually designing; in CoX you basically had to build the thing in order to design it.
A little sad to see this topic didn't get more responses