The difference between you and me is that I've seen enough different notions of object (and defined some of my own) that I don't believe there is any such definition. In class I discuss why, but it's difficult to transcribe such an interactive discussion; but it is essentially the other side of "this conversation again, and again, and again".

I don't find your definition particularly useful, either: it's too encompassing to really be of much use _to me_. By this definition just about all computation is an "object", which doesn't really tell me anything interesting.

Also, as a general pedagogic principle, I'm opposed to definitions that are too vague to say much to a middle-of-the-pack undergraduate. I'd definitely put your definition of objects in that space. It sounds like good stuff—it's certainly "quotable"—but the typical student would be hard-pressed to actually explain it or put it to use.