Suggest move the hasName data property to the relations ontology. Many things that are not agents have names . Then there may be no need for relations ontology to be importing agents ontology. It seems a bit backwards.
Suggest move identifies(isIdentifiedBy) properties to the relations ontology. Many things that are not agents have identifiers. Then the agents ontology can import the relations ontology, like most other ontologies do.
Suggest change name of rel:hasUniqueIdentifier to rel:hasUniqueString to avoid confusion with the class, Identifier.

Properties with too narrow domain and/or range

...

isMemberOf should be general, now there is need to create a isGenericMemberOf.
UPDATE: this may have been fixed now.

Recommended Additions

hasVersion string valued.