I suspect the black screen is likely an incompatibility between the virtual VMware SVGA driver (from Fusion 5) and Fusion 8. You may want to upgrade the hardware compatibility of the VM to version 12 also.
If you want to try to boot to "Safe Mode", what you could do is "Power On to Firmware". This will bring you to the virtual BIOS screen; which makes the keyboard active within the VM allowing you press F8 to boot into Safe mode once you exit the virtual BIOS. If you let the VM power up normally, things happen too fast for the VM to have keyboard focus and let you press F8. Once in safe mode, you could attempt to reinstall the VMware Tools (along with the updated VMware SVGA driver).
