Hi Jordan,
Thank you for your reply. I ended up just using eth0 for the WAN and running all 3 VLANs into eth1. Problem solved! Now I can use the offload, and the CPU utilization when pulling 400mbit over the WAN went from 75% 20 20% if that. Nice. The reality is that with the ER-POE5, it seems that if all you needs is a non-POE router as in my case, just use eth0 for the WAN and eth1 for the LAN and forget the switch. Thumbs in armpits and a big, dorky grin. The ER-POE5 is a spectacular router, period. And for the price... Unbeatable.
Thank you!