Can the Copula Be Split From its で-particle, as in「学生でも子供でもない」?

Question

The sentence

学生でも子供でもない

translates to

[It is] neither a student nor a child.

Initial Questions:

1. First, just confirming: the use of でも here is just で + も, and has nothing to do with with the conjunctive でも, correct?
2. If we instead wrote the sentence as

学生も子供もではない

would the sentence still retain its original meaning? (Here I replaced the two で's with a では, placed right before ない, as we usually see the negative copula).

Main Question: Is the main reason that the original sentence splits up the で's as follows:

学生で子供ではない

..is that the copula is actually just the で particle + ある (or the more archaic ござる, which also means "to be")? If so, it would make sense why で can be split from ある (in its ない form) form and placed after 学生 and 子供 (the the two nouns that "It" is not "within the bounds" of).

Answer 1

学生も子供もではない

That is not correct. In Japanese the tense/negation comes always in the end. You need to say the copula both times to make it clear that you are negating the state of being of both things.

That is why: 朝ご飯を食べて学校に行くand 朝ご飯を食べて学校に行った have different meanings even though it's just the TE FORM. "will eat" and "ate".

学生でも子供でもない

Being also a student, being also a child, is not. You're doing just like the previous sentence: negating/applying tense in the end.

  学生で子供ではない

That means one is a student and not a child. Not really excluding anything.

And yes, である is copulaで+ある which means literally exist in the condition of being X.

First, just confirming: the use of でも here is just で + も, and has nothing to do with with the conjunctive でも, correct?

Correct.