I've never used WINE, but ROLF certainly isn't an emulator, and there's no RISC OS involved.
There's also no X windows involved, the system uses the plain vanilla frame buffer, although the API allows for optimisation/acceleration transparently to the applications.
The aim isn't really to run RISC OS applications, although the behaviour of the GUI, as well as how it looks should be conducive to that (the GUI is co-operative, for example, but with true independent threads).
I've got a dozen applications running on this RISC PC. Toss in a couple that I'd like to have, mainly to do with digital video, and that's probably all the GUI applications I personally need to work with the system. To get them, I could write them from scratch, modify existing GTK applications to play nicer, or make it possible to run RISC OS applications, via re-compilation, emulation (QEMU) or BASIC (Brandy), combined with a RISC OS SWI compatibilty layer. It all comes down to which approach is least effort.