worst case scenario

This fourth, apparently completely meaningless book of the Twilight series begins where the third book ended.
To make a long story short, here the plot:
Bella has taken a decision, the wedding will take place and it goes on for Honeymoon. Everything completely unspectacular at best funny but totally loveless.
Before and during Honeymoons still fast two new elements are introduced into the story with a crowbar to get it nice to say, that of Tanya and Irina's fate, and the legend surrounding the Incubus. The latter is hardly mentioned, because it proceeds even into action and impregnates Bella that developed from there to a really perverse appetite for eggs.
The view changes to Jacob I felt as relaxing because, although the whole werewolf thing was very boring for me, but Jacob was blessed with at least some of its old character strengths and also some sense. He describes Bella's pregnancy very well, and also for what it is: monstrous.
However happens in this second book is not really anything, apart from the developments between Jacob and Sam, Bellas discovered passion for blood and Edwards acceptance of the baby.
In book three but then comes the meltdown: Bella Mary-Sue Cullen.
You can do everything, knows everything, does everything right and is indeed soooooooo "amazing" and now really graceful.
You can hold your breath while he suddenly hunting and races just like this before people who cross her path, she can hold her baby, hug Jacob, see Charlie, she worried completely senseless way false papers for Jacob and the baby with the completely stupid name Renesmee, she trained and howls on each side if their anxiety around and then let the big, long announced fight for victory by means of its Mary-Sue-shield burst. Jaaaaa, the book was a real treat.

I ask seriously as an author, with the acquired practice while writing three really long books can write something together.
The characters act, think and no longer develop within their role or their own character story. Jacob is reduced by having to love the child of his beloved Bella and the bloodsucker, Edward is no longer recognizable and is so effeminate and not more smart or charming that he shoots far beyond the status of "Cuddle Vampire" and for me as a small group misery somewhere along the wall crawling.
Charlie's reaction to the whole vampire story are so extreme irrational that I wish that thing called Renesmee would eat it and that we should be even with the greatest horror of some 700 pages: Renesmee. The incarnation of goodness, beauty and charm ends. I have seldom read such a thing absurd.
The showdown fizzled as the actual thing with the wrong Papieren- Seitenfüllerei and for the first time during the whole series, I noticed that S.Meyer actually writes as for children. You have the characters of each coven can not describe easily, it lacked any finesse and the opinion of Mary-Sue-Bella to me no longer cares for her transformation.
I can not speak of disappointment, but only by a lack of understanding. What else is left, if you observed how a writer from book to book but further breaks down the fourth book so suddenly out of space is that you want to burn it?