Hi,
1- I've got some doubts on the fact Workbench will grab 2 "processors" (be it two "cores" of a single processor or two separate single-core processors). Anyway, under the "solver options" you can freely set it up as you like.
2- This is definitely not true for Classical. You have to "force" it to use two "processors" (or more, depending on your license) within the Product Launcher or with the Ansys Settings File
3- PCG does take advantage of two "processors", at least as long as we're speaking about two cores of a single physical processor. Never did any testing with a true multi-processor machine. However, the conditioning part of the Solve process is not multi-processor-ready (you can see that because in that phase, the Task Manager shows a max of 50% processor occupancy).
Regards