IP – Relationship Between IP Address and MAC Address

One key use for per port MAC addresses on switches is for Spanning-tree BPDU's. These are Layer-2 multicasts with source MAC address of the egress switch port.

I would have to brush up on other Layer-2 protocols such as TRILL and SPB, but they might also take advantage of a per port MAC.

Does that help?

You can enable DHCP snooping, ARP inspection, etc. A host with a statically assigned IP address would need an exception to be manually entered in the switch for the port where the statically address host is connected.

You can also use 802.1X to verify that the host is allowed to connect to the network. This requires more infrastructure than just the switch.

You can also use VACLs to restrict traffic.