There should be a way to extract a list of Inputs from the getEntity API, similar to what was done with the nodeTemplate.getSubMappingToscaTemplate().getInputs.NodeTemplate Get Inputs for a VF
ArrayList<Input> inputs = vfNodeTemplate.getSubMappingToscaTemplate().getInputs();

To have an ability to extract inputs per VF instance in the Service there should be additional getter getInputs for the class EntityDetails.