Yes and no.
The WCS is always on. The UCS as you know it from AutoCAD is not available.
You can, however, reposition the WCS origin in 3D space and rotate the grid in the plan - as you probably already know. However, the XY plane stays horizontal.
The modeling methods in Archicad are tool based, not geotmery based. In AutoCAD, you assume that a set of spatial points and planes are a wall, door, roof, whatever - in some vertical solutions like ADT that intelligence is built it to some extent. Achicad treats elements in a certain way and you have to know what the constraints are.
I personally have not found anything that cannot be modeled or imported (organic shapes) in Archicad, this way or that way ...
Please add your Archicad version and OS details to your signature.
HTH,
Djordje
ArchiCAD since 4.55 ... 1995
HP Omen