I have already typed at least 6-7 chapters of this book I've been focused on, but what I want to ask is, is it wise to post what I have so far online for feedback? Or am I just setting myself up for someone to potentially come across my work and steal it for themselves, and if/when my book is complete and published, would you or others already be too familiar with how the book will turn out and not bother with it?
Also, my book, which I have two sequels in mind for (those are for another time), will have supernatural beings in it, but no vampiric creatures of any kind (they will be non-existent in my book/series' universe, but will include three species of werewolves in the overall series I have in mind (two separate, the former called Rougarou or Roug for short, and Dire Hounds for the latter and one hybrid of the two which I plan on naming "Lybrid"). The first book will be mostly "grounded" but will be "peppered" with "unexplained occurrences" (how much I'm not sure yet) throughout. Oh! And my main character will be mute and communicate primarily in American Sign Language (though to be honest I have no idea how to portray it in the book, as I am writing using Third Person Multiple POV), while also suffering from a degree of amnesia (for how long I have not decided just yet, but probably until the end of this sequel idea).
I have never posted any of my work online before, let alone for advice/feedback, so should I do it? Or am I just being overly cautious?
I'm thinking about not including a prologue. Is that a good idea? Bad idea? Or is it down to personal preference?