No apologies necessary, I did indeed use a newtonian object as the particular for ego in the first analogy. In regards to abstract forms and mental constructs as not existing in the same manner as objects, I'd disagree with you and the OP and hold that they do exist, at least in the same manner that everything else can be said to, if anything else is said to. In other words, I would assert there is no difference in types of existence nor duality between existence and nonexistence, object and nonobject, that is derivable and non-arbitrary. What I would concede is that an ego (and everything else) is "empty" of perfect causal independence. In other words, it must be emergent and generated.