It seems that I have enough though; maybe it's not automatic swap mounting?
Any help on getting hibernate working is appreciated.
It is not a good idea to hibernate your Virtual Box virtual machine to the virtual disk swap. The appropriate way to achieve hibernation is to close your virtual machine with Machine -> Close (or just close the virtual machine window):
Choose "Save the machine state" for "hibernating" to a file on your host partition.
You can also do this from command line on the host with the following command:
VBoxManage controlvm <name> savestate
<name> by the name of your VM.