[Jason Barton]"QUESTION: should I store the AE CC projects on the ssd with the OS and apps or store it on the ssd with the media cache?"
AEP project files are typically small and infrequently accessed. The location of the project file itself is inconsequential.
If your cache were on a mechanical hard drive, I'd strongly encourage you to store project footage on any other drive. With an SSD, which is significant faster with high quantities of read and write requests, this matter less. Put project media files wherever they fit.