I can only try, you are mistaken on various points:
1) Incorrect. The overwhelming majority of poskim who discuss intellectual property do NOT make a blanket prohibition against copying. And as I indicated above, nor is their a blanket heter to copy either.
2) Correct. On an individual basis, with the rabbonim specifying when it expires. And this was based on hasagas gvul. Not geneiva (otherwise it would have been permanent, non-expiring.) And it didn’t apply to all works, unless the rabbonim gave the sefer a specific cherem. Furthermore, it applied a temporary prohibition only to *commercial* copying-to-sell, where obviously you are taking away business from the producer who would have otherwise sold it to the customers the copyer sold it to. Hasagas gvul. It did not apply to personal copying. (Obviously there was no personal single-copying feasible in those days.)
3. No it is not “genevia”. And very few of the poskim consider it halachic geneiva. They consider hasagas gvul.
4. I explained above why dina dmalchusa is not relevant. So that only leaves hasagas gvul. And hasagas gvul ONLY is relevant if you caused a lost sale. If there was no intention of purchasing it (i.e. a $5,000 photo/video editing software), there is no hasagas gvul.
No, I did NOT intend to assert above that “intellectual property can absolutely be copied in all circumstances.” I stress only if he would not have purchased the product even if he couldn’t copy it. If I wasn’t entirely clear on that point, let me stress it again. I am asking you to respect this point even if you and some poskim may hold otherwise, as *many* poskim agree with this point. Including Rav Yaakov Shapiro, Rov of Bais Medrash of Bayswater (who can *easily* be contacted.) And if you want to “see it inside” from a halacha sefer, see Pischei Choshen, Geneivah, page 284.