If all of you have Github accounts, I think it would be easier to troubleshoot, track and discuss on Github. It would also make the solution (if we ever find one) much more discoverable for new users. We can then post here an URL to the fix when we have one.

What device are you using Spookyfid? I may have missed something but I don't see missing requirements in your lxc-checkconfig. [Edit] Oh, except maybe CONFIG_DEVPTS_MULTIPLE_INSTANCES.