The fact that naskh has been used by early Muslims to mean things other than abrogation, something we and almost all scholars abundantly agree upon, has no bearing whatsoever on the question of whether naskh in 2:106 means abrogation or not. The latter question is decided by old Arabic dictionaries, and by other uses of the word naskh in the Quran. I believe that these two sources of evidence support the meaning of annulment/abrogation (or copying/transporting, but that would not be supported by the context in 2:106).
I answered your first point, about Arabic dictionaries definition of the word naskh, in
this post. And I answered your second point, that 2:106's use of the word can only mean annulment given its context, in
this post.
I'm sorry that we disagree, but the more books I read, pro- and anti-abrogation, the more convinced I am that the word means more than abrogation and that its use in the Quran means other than abrogation.
A good example is what Al-Areedh said in his book فتح المنان في نسخ القرآن. He acknowledged the obvious conditional in 2:106 but turned pro-abrogation based on 16:101, which he understood proves abrogation did occur. Thus, he equated the words نسخ and بدل without proof. The fact that two different words are used here is, to me, proof that two different concepts are addressed.
As for your point about the usage of the word naskh in the Quran, we have three occurrences of it in addition to 2:106. They are:
in which the word clearly means correction. And
in which the word clearly means recording. And finally
in which the word clearly means inscribing.
So, the word, as used in the Quran, does not mean one thing. In fact, it is used for setting as many times as for unsetting. I just don't see how we can prove that its use in 2:106 only means abrogation.