I have no plans for a demo version.
You can achieve flat shading like in that picture, but the ambient occlusion isn't something that can be easily achieved (i'm not sure what you're asking, if flat shading is possible, or if AO is possible). You could get a look close to that though with shadows and lighting and perhaps fog.
Some 3D is visible in the editor, but it's limited since C2 doesn't allow plugin developers do to things that modify the editor. Right now you can mock up scenes with boxes from a top/side view, there is no "movable" camera even though i'd like to add one. The default camera setup matches the view in the editor. hopefully C3 will allow me to do more. In practice it's not a big chore to set things up even with the limited editor view.
The light mapping isn't done in C2 (again editor limitations prevent me from adding this kind of thing, and hopefully it'll be possible with C3), it'd be up to your tool, but theres support for secondary UV's for a lightmap texture if you want to apply a lightmap to objects made in your 3D software independent of the diffuse map.