LXD configuration?

So far, not real impressed with LXD. It's documentation is non-existent and for a small home installation with a couple of virtual machines it seems to provide no additional features than LXC while increasing complexity and confusion.

How do I:

1. Modify the configuration of LXD to bridge containers' eth0 connection with my host's br0 interface? I changed /etc/default/lxc-net to USE_LXC_BRIDGE='false' but I get a lot of
   
   
   Code:

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   Apr 25 14:53:07 nas systemd-udevd[2783]: Could not generate persistent MAC address for vethNJ6IOJ: No such file or directory
Apr 25 14:53:07 nas systemd-udevd[2785]: Could not generate persistent MAC address for vethPVTJAQ: No such file or directory
Apr 25 14:53:07 nas libvirtd[1496]: Failed to open file '/sys/class/net/vethNJ6IOJ/operstate': No such file or directory
Apr 25 14:53:07 nas libvirtd[1496]: unable to read: /sys/class/net/vethNJ6IOJ/operstate: No such file or directory
Apr 25 14:53:07 nas systemd[1]: Started ifup for vethNJ6IOJ.
Apr 25 14:53:07 nas systemd[1]: Starting ifup for vethNJ6IOJ...
Apr 25 14:53:07 nas systemd[1]: Stopping ifup for vethNJ6IOJ...
Apr 25 14:53:07 nas ifdown[2818]: /sbin/ifdown: interface vethNJ6IOJ not configured
Apr 25 14:53:07 nas systemd[1]: Stopped ifup for vethNJ6IOJ.
Apr 25 14:53:07 nas libvirtd[1496]: Failed to open file '/sys/class/net/vethPVTJAQ/operstate': No such file or directory
Apr 25 14:53:07 nas libvirtd[1496]: unable to read: /sys/class/net/vethPVTJAQ/operstate: No such file or directory
Apr 25 14:53:07 nas systemd[1]: Started ifup for vethPVTJAQ.
Apr 25 14:53:07 nas systemd[1]: Starting ifup for vethPVTJAQ...
Apr 25 14:53:07 nas systemd[1]: Stopping ifup for vethPVTJAQ...
Apr 25 14:53:07 nas ifdown[2827]: /sbin/ifdown: interface vethPVTJAQ not configured
Apr 25 14:53:07 nas systemd[1]: Stopped ifup for vethPVTJAQ.

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2. Create configuration files specific to a particular LXD container so that I can specify fixed MAC addresses to use?
3. specify starting a container with a specific configuration file. attempting 'lxc start --config=/path/to/config name" yielded a stupid warning about missing config.yml not being a directory. What is config.yml? I cannot find anything on a search about lxd and yml.

LXD documentation needs some serious updating. Otherwise it's just a DOA toy to launch a trivial example with and then quickly be apt-get removed because you can't figure out to adjust it to your specific needs.