The message:
The thing that intrigued me the most throughout the 2nd Part was the message the story was trying to convey.
In her dying moments, Kakyuu prays for a time when the battle between light and dark ceases to exist and that they (Sailor Senshis) can have a peaceful life.
Lethe & Mnemosyne have a similar speech condemning their suffering onto Usagi's light and Chaos.
Similarly, for all of the Animamates, the concept of being a Senshi was what led to all of their bloodshed.
Even in Eternal, we see that the Inners & Outers have to renounce any peace because they are a Sailor Senshi.
For several times, Usagi is blamed as the source of everything because she is in possession of the Silver Crystal.
Being a Sailor Senshi is a miserable existence and everyone, except Usagi of course, has had nothing but pain and suffering in the end.
Being born as a Senshi is synonymous to a life of tragedies and loss and that is what seems to be the point of the movie.
Usagi however prefers to embrace the good while Galaxia embraces the bad.
Even Galaxia herself comments on this and laughs at the faint concept of life because Senshi will always be reborn.
They can be given birth as easily as it is to kill them so life has little importance to her.
Later on, at one point even Usagi seems to have made her peace with her destiny - there is life and death, joy and pain, light and darkness.
In the end, Usagi sacrifices herself calling on to all of the Senshi of the universe slumbering into the Cauldron as well as to her fallen comrades to lend her their strength so that she can extinct Chaos.
It's all of the Senshi that exist vs Chaos and I really like it.
Yet, after her sacrifice she is given the easy choice to return home along with all of her friends... It's just feels anticlimactic.
Furthermore, before we all thought that Cosmos was from the far, far future and thus even if Usagi gets the perfect (and selfish) ending, it's OK, the girls will eventually lead a happy and peaceful life.
But no, that's not the case, like Kakyuu, Lethe and Galaxia lamented on, in the end because of Chaos who is attracted to Usagi's light, more death and tragedies will occur.
So what was the point of everyone commenting on how the battle of light and darkness should be stopped?
I would have preferred that Usagi made a deal with the Cauldron - she destroys her Silver Crystal and shares her light to the still budding Star Seeds so that they'll too have the same strength to embrace hope as her.
With her death and sacrifice, even though Chaos will eventually be reborn, it will never become as strong and dangerous as the Silver Crystal will never exist - light and darkness are equivalent, without an infinite light there won't be an infinite darkness either.
Of course, Chibi-Usa wouldn't exist and neither would Cosmos' devastated future.
In exchange, she requests her friends are sent back home without their Sailor Crystals instead of being reincarnated as new people; everyone finally gets to have a normal life and decide of their own path in life liberated from the shackles of being a Sailor Senshi and Usagi truly becomes the messiah who saved the Galaxy, a fact known only to her few comrades.
A bittersweet ending.