Given that you want to you a public IP range (66.xx) you'll want to increase the number of NICs you're using. Assuming you're not using software iSCSI or NFS for storage then I would suggest adding 4 NIC ports and configure your host like this

1) 2 NIC ports (different physical NICs if you use dual/quad port NICs) - create on virtual switch (vSwitch) and assign you management IP to ESX for this (10.10.11.xx). This is where the management port for ESX would exist
2) 2 NIC ports in a DMZ vSwitch for the VMs that you'll have in the 66.xx network. These 2 NIC ports would be physically connected to your DMZ switch. The important thing to note is that ESX will not have a IP presence on this vSwitch. That protects your ESX host from DMZ network attacks.
3) 2 NIC port for your 3rd C class - this would be your 216 network. Would you have that in another DMZ?

You could do this with 2 NICs in a single vSwitch and VLANs, but it would be ideal to seperate things out. Unless you have a specific reason, you should remove the 66.xx.xx.xx IP from your ESX host. It won't need it for you to run VMs in that IP range.

Could you describe how your host connects to switches for the various networks? I.e. do you have seperate switches for each? If that's the case then 2 your current 2 NIC ports you'll want 2 vSwitches. One will have a virtual machine port group for the 66 network and will only have one NIC port. That port will be connected to your 66 network physical switch. Another vSwitch will have the management port for ESX and the 10.10.11.xx IP assigned to it. This switch will have the other NIC port and will be connected to your management LAN. You would then add a 3rd NIC port for 216 network. If the 66 /216 network share the same switches you could seperate the traffic with VLANs.

If you're using 2 seperate switches for the 10 and 66 networks then you'll need to configure 2 vSwitches - each with one NIC port. So you can get away with just 2 NIC ports for now. Personally I wouldn't expose a management port to the Internet. The convinience is not worth the network risk.

The network range you see on a vSwitch is just a guessimate of what ESX thinks is on the subnet based on broadcast traffic. It does not limit which IPs you can use for your VMs.