Sure thing. I think this example will help a lot of people and demonstrates some of the tensor level features of ITensor.
About getting all of the energies: if you use
and then print "d" (Print(d);) then you should be able to get all of the energies that way.
Yes, it certainly should be possible to extract the storage of an ITensor and export the data into another code such as an ED code. There is a "code formula" about extracting the storage of a dense tensor that should help you. Eventually I want to fully document the storage types and the storage system, which is actually really flexible and interesting (if I may say so myself).
If you have some questions about accessing ITensor storage data or creating ITensors from some data directly, post a specific question on here and I can help you out.