IPX over DMVPN will not work unfortunately. It's not so much DMVPN, but the fact we removed IPX from the NHRP code some time ago (back in 12.2 IIRC), and DMVPN uses NHRP to find its next hop. It works for IP as you know, but there's nothing in NHRP anymore for IPX.
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...