Harley Considering this was six years ago im assuming you dont need any more answers but if someone else find this one idea is to read the main books then go back and read the novellas. Its what im doing. You might not enjoy it as much being mad at characters for something you know they do in the future that they dont know but youre still loving the books.
Nes Read the novellas. Not necessary, but you won't get the full experience unless you step into Warner and Adam's heads and understand how they think, especially towards themselves, Juliette and the Reestablishment.
Kylie You do not need to read the novellas, but if you want to step into the world a little farther and understand more about Juliette and Warner, then do it! The writing is beautiful, as always!
eirylle conejos I think that you should read the novellas as well, because you will see what the other characters had in mind. You will get a glimpse into their world but its your choice anyway. but i highly recommend that you read it