Did you ever use minishift? It behaves in the same way, all the data is inside the CRC VM. If you manage to get into the CRC VM, and you get to /mnt/pv-data then you'd see lots of directories pv0001, pv0002 etc. If you create yourself a PVC then it will automatically attach to an existing PV's, so yes you can use it for applications if you want.
minishift used to have an option, "minishift ssh", which would ssh into the VM that minishift was running inside. But I can't see that as a command-line option for crc.
On my windows installation of crc (it has since expired), I found the ssh private key for the instance at
You can get the ip of the VM with "crc ip"
I'm not totally sure what the ssh username is, but it's probably one of crc, core, openshift.
C:\Users\<username>\.crc\machines\crc\id_rsa <ssh username>@<vm ip address>
I used that technique once when ssh had died and I wanted to restart ssh without restarting the whole machine.
You might need to use kubeadmin or some privileged user.
Anyway, good luck.