There are several IPv6 -> IPv4 interops (bridges) developed already. All of them appeard due to slow IPv6 adoption. Some of them are: NAT64, XLAT6, DS-Lite.

Never heard about ND tables overflows? They fixed one thing, broken another. ARP poisoning is mostly fixed problem.

I like NAT myself. Im dualhomed (el-cheapo), using policy routing and NAT. Everything works like a charm. I cant imagine such setup w/o NAT actually.

SLAAC might be great thing for you, but not for others. This is why IPv6 is such a failure. Instead of creating simple protocol to meet middle ground, they slapped together annoying techs for specific cases like IoT. Great job.