You only need to know a couple of things.
Of course, you will always have the rights of your creations, the books you send will appear always with your complete name.
As you will send your books by email, you will have the evidence of having done it for any doubts about.
Also, our mail service is hosted by Google, so we can't alter the logs to "erase" the submit.
No, you can't. You must give the readers at least one opportunity to choose the path of your story.
But maybe you have a finished story to publish. In this case, you can "alter" the final chapter to give, at least, two different endings.
It's not the ideal, but in some way, the readers can participate.