I think DH is the study of how the interaction between computational methods and human sciences change each other, meaning how their dynamics evolve and how that evolution shapes one another.
Concerning the object of study of DH, I think it is not a non-identifiable matter, instead it is about the human sciences researchers’ common needs related to software and interdisciplinary approaches, plus the sustainability of communicational bridges between disciplines and the constant critic of hierarchical structures that might try to impose a certain agenda over the research interests.
Finally, regarding this discipline’s methodology, I think I don’t have yet a clear idea about, but I see it as a kind of criticism and prerogatives to the definition of standards across cultures and epistemological perspectives; but this is just an opinion and I recognize the need to investigate this issue more deeply in the specialized literature.