Knock on wood, adding 2 GB of memory to the hosting VM (6 GB total now), may have helped. I have been able to stream a video off the VM housing the ZFS array. Time will tell if this is a fix as I have got this far before only to have it fail in short order.
Hopefully this is the fix. The USB card I added turned out to use a NEC chipset and I have been stuck in firmware hell trying to get it usable under the VM to no avail.