Maybe just live with TrueNAS for a month or two and get to know it on a friendly level first?
I think I'm still not understanding the need for LVM. Help me understand. I see ZFS on TrueNAS as a combination of mdadm and a file system. I'm not sure I even have partitions. My ZFS pool is just using the whole drive, but that was all I wanted. Are you planning on using your drive space for other things? (Plex server in a jail, or remote real-time storage for instance) If so maybe LVM would help isolate backups - which I thought was why you wanted this machine - from a VM of some type running on the same machine - which I don't think you've suggested.
> My network card is out for delivery. A few days late but better than never I guess. I'll see if the drivers needed for it are available as modules or not. I suspect they are tho based on info in this thread.
Good luck. Hope the new card makes your life easier.