Hello Brian
First of all a clarification. There’s a difference between “static routes” and “statically configured EIGRP neighbors”. I assume that in your post, where you mention the former, you actually mean the latter.
So can EIGRP static neighbors be configured over regular Ethernet links instead of over Frame Relay? Yes, you can. However, there’s no reason to do so. The feature is useful for technologies, such as Frame Relay, that don’t support multicast. Unless there’s some obscure configuration scenario that needs it, since Ethernet supports multicast, there’s no reason to do so.
As for the method of configuration, Nexus devices use the ip router eigrp command on the interface to indicate which interfaces and their corresponding subnets, will participate in EIGRP. In addition, things like summary addresses are also applied to interfaces rather than the EIGRP router mode configuration. This simply has to do with the syntax of configuration, and not so much on the actual operation of EIGRP.
EIGRP is also configured differently when IPv6 is used, or when EIGRP named mode is used. To familiarize yourself with these and the method and syntax of implementation it will simply take practice.
I hope this has been helpful!
Laz