I have just published a bug fix for Copy and Clone of CMS pages.
Now when you copy or clone a page it also copies across all the includelets on that page, and preserves keywords and relations for that page.
Though it does not publish the new page - after copying/cloning you can make any required edits before publishing it.
The only real difference between Copy and Clone is that Clone immediately creates a new item called "Copy of <title>" whereas Copy requires you to then also click the Paste button in the folder of your choice.
Note that if you want to move a page, or recover a page from Trash, I still recommend using Move rather than Copy then Paste. This will prevent having duplicate pages in your content, will preserve the revision history and publish status, and will also mean that if any other pages have the page as a related item then it will also be preserved.
Enjoy!
Joe