Use of choke to create analog ground: mistake?
That's old practice.
PCB paritioning does not mean what you think it means. Partitioning means to separate components to different regions of the same single continuous ground plane so return currents of a noisy section don't flow under a sensitive section. Partioning components is better than splitting the ground plane (which is what your schematic is doing is called). It's really easy to make things worse by splitting than if you just did nothing in particular.