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.
It's definitely possible that there is no one good definition, but it's a good discussion to have. I applaud that you treat this with your class.
The usefulness is debatable. To me, it's been useful because it helped me see that, for example, a process can also be an object, and you can apply object oriented rules to interacting processes. The Actor model is an extension of that. Modelling a set of Microservices as an object model has also proven valuable.
How you communicate it to students is a not an easy matter. I'm opposed to giving definitions as an absolute truth if they aren't, even if you're doing to prove a point. If you want to teach with different definitions, that is of course perfectly fine, but at least a mention of the debate could solve some later problems. People tend to adhere to the 'laws' they learn for a long time, and if you teach them a definition that is incorrect in some cases, they'll have trouble with those cases.
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.