Nowadays rights can exist when chapters are being written, even if the book is not finished.

Recording drafts, individual chapters, is not only possible, but advisable if, in addition, they are going to be shown publicly before finishing the work. It will be the judge who decides, in the event of a conflict, whether there are rights over those paragraphs. It is always better to have evidence of those paragraphs than not to have it. These tests, of course, support and reinforce the record of the finished work.

If two or more people are authors of parts of a text, they can be registered with a pdf file or similar and invite the other authors to accept that they are co-authors.

Another typical case is that someone is the author of the text and another of the illustrations. In that case, it is best to register using an .rtf file or similar, the text on the one hand and the author of the other works, in their own image category. In the final book you can report on the different records of the works that are in that work.

In general it is not necessary. It is very common for errors to be found even in later editions of the same work. That does not mean that the first proof of declaration of authorship of the original text is no longer useful. It is only advisable to re-register if the work changes a lot. For example, with the disappearance or appearance of many paragraphs that cause part or all of the work to change meaning.

In general titles do not generate rights of author. In fact, it is easy to find works of the same or different types with the same or very similar title. Only in some cases can the title be considered protected, such as when the name of one of the characters appears in it, for example. A classic example would be “Alice in Wonderland.”

If you want a generic title to not be used by other people, you would have to consult a patent, trademark and trade name office to study if it is possible.

What does automatically generate rights is the literal text of the book itself, the work itself.