> ready for review

I think it might be a good idea for KSK2010 trusted-key, without any other
keys, to be fatal instead of a warning.  As a managed-key can be a warning.
Maybe add a suggestion to remove it from named.conf and rely on bind.keys?

I would consider being more verbose in the DLV warnings and saying ISC DLV
is shut down.

The code itself is fine.