I think that I quite understand the relation between ontology and "logical syntax" of language as it is presented by Wittgenstein in Tractatus. He states that there are atomic entities, which are mysterious (Wittgenstein does not give any examples whatsoever), simple and unaltered objects. Their existence is some sort of theoretical postulate (thesis 2.0211). In what follows I will denote the class of Wittgenstein's objects as W-objects. On the level of language W-objects correspond to names and only to names (thesis 3.221), but it seems that they also have certain logical type assigned to them (thesis 2.0123). There are also states of affairs, which are configurations of W-objects. On the level of language they correspond to elementary propositions, which are configurations of names (thesis 3.21). Finally there are propositions which are truth functions (in the sense of classical propositional calculus) of elementary propositions. Here we have it - the pictorial theory of language.
There are of course various subtleties involved in the tractarian view on logical form of language and its relation to ontology, which are very interesting in their own sake (especially for someone trained in mathematical logic and formal onotlogies), but here I am curious about (as most of readers) mystical part of Tractatus.
To motivate my question note that Wittgenstein was influenced by Schopenhauer. It was Schopenhauer's idea (he was philosophical descendant of Kant), that one's will is a thing in itself in the sense of Kant. I think echo of Schopenhauer's influence is reflected in solipsistic theses of Tractatus (5.62 to 5.6331) and also in thesis 6.43.
Does Kantian notion of a thing in itself is an analogue of W-object?
Does Wittgenstein consider self or one's will as an example of W-object?
If not, then can answer be somehow deduced or just explained in terms of the ontological/logical part of Tractatus?
Secondly, Wittgenstein was also influenced by G.E. Moore and this philosopher argues in his famous Principia Ethica that the good is a simple, unaltered entity. On the other hand I think that the good was not considered as a W-object in Tractatus according to thesis 6.4, I found this thesis unexplained - just stated.
Does it follow somehow from the ontological/logical part presented in Tractatus that the good cannot be an example of W-object?
By "A is an example of a W-object" I mean approximately that "there exists a propositional function f(x) with one free variable, that belongs to the perfect language Wittgenstein describes in Tractatus such that A can be substituted for x in f(x) (f(A) is a valid sentence)" or "expression A is a part of some sentence S of perfect language that Tractatus postulates and A occurs as a name in S".
Further edit - in response to Conifold's interesting remarks on relation between logical positivism and Tractatus
In twentieth century philosophy there was an extensive discussion between proponents of metaphysical and positivist interpretation of Tractatus with all its subtleties. There are serious arguments supporting either position. But regardless of the possible outcome of this discussion I am interested in the following question.
Let us get rid of all theses of Tractatus after thesis 6. The result of this operation I denote by T-restricted. The question: Is thesis 6.4 logically independent from T-restricted or there is some explanation or at least indication that someone accepting T-restricted should seriously consider accepting thesis 6.4?