Generally speaking, the more one copies the more risk involved as, eventually, one is likely to copy too much or copy the wrong thing.
It is true that titles and short phrases are not protected by copyright. Short phrases can, however, be protected by trademark law. But lets assume there are no trademark issues - a good assumption. Can copyright ever cover a title or group of titles or an outline? perhaps.
Copyright covers creative expression, not ideas. For example, data is not covered by copyright, however, a creative organization or arrangement of data can be protected by copyright.
Copying the entire outline of a book, word for word, could cause you a problem. Remember, you can be sued for good reason, no reason, or bad reason. Hopefully you will "win" if someone sues you for no reason or bad reason but who wants to spend many thousands of dollars to "win" a copyright infringement suit? Such is not a "win" to me.
So I submit it is best NOT to take actions that might anger others even if such anger is unjustified (if there is a way to avoid such actions). Copying the entire outline of a book, word for word, may not be copyright infringement but it may anger the author of such book into doing something stupid like suing you.
So my recommendation is to at least change the titles enough to avoid copying them word for word. Then you should be safe as I suspect there is no protectable creative expression in the arrangement of the material of the book. But such is a guess without seeing the actual material and the extend of copying.
Please keep asking question until you are satisfied with my answers.