Can I use a paid engine as a basis for building my own engine?

Question

CMS

If I rewrite the entire code of a paid CMS in my own way, cut out the functionality I don’t need from it, replace the CNC with my own. In general, I will make almost a copy, but sharpened personally for me and written in essence by me, but in the image and likeness of the existing CMS. To what extent is this action legal and can the developer company sue me in the future?

Answer 1

copyright protects the implementation, not the architecture/ideas/approaches.
if you write completely your own, but with a similar structure, then there will be no problems.

Answer 2

If I rewrite all the paid CMS code in my own way

Write from scratch then.

Answer 3

Can sue. There were cases when even the owners of a completely rewritten code, but with stolen logic, lost in court.