Well, getting VNC and SSH working was easier than I thought it would be. Just 15 minutes to do both. Still a LOT more to learn but it's easier than learning Fortran was in 1968!
I've attached the latest dmesg file after a fresh reboot with the CM-19A plugged into an OTG adapter without the hub. Thanks again for looking at it.
Ok you're CM19a has been detected and correctly identified
[ 1.521744] usb 1-1: New USB device found, idVendor=0bc7, idProduct=0002
[ 1.521769] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 1.521782] usb 1-1: Product: USB Transceiver
[ 1.521792] usb 1-1: Manufacturer: X10 wireless Technology Inc
The kernel OTG device driver being used by the USB hub is struggling to manage the i/o of your USB devices. There is quite a few errors in the dmesg to this effect. I reckon the hub chipset is not properly supported by the kernel
What you really need to do is power off, remove the hub completely, plug the CM19a directly into the Pi Zero and then power up the Pi Zero. No keyboards and no mouse. Then paste the results of the dmesg and the lsusb. Also type lspci and paste the results of this too.