Stop iCloud sync and delete files on iCloud ONLY

Hi, I like iCloud for syncing certain things like Pages and Notes shared with my iPad. I DON'T want it storing and syncing everything else. Other people have asked how to remedy this and to date I have not seen a satisfactory and clear answer on how to do it. I want to keep the files stored on my iMac and remove them from iCloud and stop the syncing. I do NOT want to delete BOTH iCloud AND local files, which is what Apple seems to have set as a default process. Please help to resolve this issue. Thank you.