の in Verb＋のじゃない: Nominalizer or Explanatory?

Question

A friend of mine jokingly came up with this sentence:

家を動かすんじゃなくて、引っ越すんだ

As I see that （こうするのだ。ボールを投げるんだ。） pattern enough, I interpreted it as a light imperative, a person showing other person what to do: You're don't move the house, you move to a new house (that's what you do). Then, someone else asked are those の's nominalizers or explanatory, which I was at a loss to in regards to sorting out the usages against grammar.

I'm guessing that they both are explanatory, answering an invisible question (このゲームをするにはどうすればいい?), which may not have actually been even sought for by the other party.

The の in こうするの definitely sounds explanatory. So the の in こうするのだ is explanatory as well.

I think what I'm having a hard time imagining is the explanatory with a じゃない tacked on it. According to Tae Kim's Guide, the explanatory の can have a じゃない tacked on it:

こうするのじゃない。

While I get the meaning is simply negation of こうするの, I can't see it as providing any explanation. It feels much more like:

（君がすべきことは）こうするのじゃない。 (Nominalizer の)

I suspect if you think about the sentence as a negation of V＋のだ, it's just the negation of the explanatory tone, and that's what it usually is.

こうするの　vs
こうするの。。。じゃない！

However, because by adding stuff it's possible to make such sentences as below, there's a certain level of ambiguity. Though it should be clear by context. Correct me if I'm wrong, but I'm fairly sure that the nominalizer の cannot be turned into ん.

（君がやるべきのは）家を動かすのじゃなくて、引っ越すのだ
（明日俺がするのは）家を動かすのじゃなくて、引っ越すのだ

Is my line of thinking on track? I greatly appreciate the help!

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Edit: To clarify what I'm asking a bit:

1. How do you grammatically categorize ボールを投げる（ん/の）だ
2. How about ボールを投げる（ん/の）じゃない? (I concluded that they were both the explanatory ん/の)

3. I know you can use the above two phrases to (more or less) instruct someone else. Could use you ever use those phrases towards yourself to provide an explanation to someone who for 1) Is asking what are you are going to do, and 2) Seems to think that you are going to throw the ball.

4. 家を動かすのじゃなくて、引っ越すのだ can be interpreted as above, but it also sounds really similar to XじゃくてYだ。 Are there any valid ways to interpret the の-particles in the above as nominalizers?

Answer 1

Explanatory tone or imperative usage are nominalizer の when it's the predicate of the sentence. It's essentially the same thing. For example, you can regard 見るのは信じるんだ as explanatory tone or imperative but never "to see is to believe", which is 見ることは信じることだ. Likewise, you can interpret 家を動かすのじゃなくて、引っ越すのだ as the nominalizer, but that means it's either explanatory or imperative. (When it's not the nominalizer, it's a pronoun. i.e. "not one to animate the house but one to move")

As for question 3, yes, ボールを投げるんだ can be an explanation to those who are curious, and ボールを投げるんじゃない？ can be a wild guess.