The point of the movie is to be found... POSSIBLE SPOILERS

...in the following question:

"How do you stay in control of your feelings? How exactly do you connect your endlessly repeating life with your memories of the past? . . . Yesterday, last month, even last year - you make no distinction between them at all."

It's about the daily grind that sets in once people have settled down and the exciting time of youth is over, coupled with the Buddhist belief in reincarnation, which makes death only the beginning of another torturous existence, and about love existing in that grind. Oshii takes this to the extreme by even taking away the beginning and the end of this life grind, youth and death through the use of clones, who may or may not ever have experienced youth and who do not die, except when killed, and even then only to return a few days later. Furthermore, their occupation is to kill other clones just like them in a meaningless war, which provides welcome relief through the excitement of the dogfights, but that is purposefully kept going on indefinitely, keeping any side from gaining a decisive advantage by various means (like the teacher and allowing the air-raid on the Rostock base) and becoming nothing more than an ever-repeating daily grind. Different characters react to this in different ways.

Tokino accepts life and enjoys it in a hedonistic way. When confronted about this, he points to the fact that he is, after all, a child. He does have genuine feelings for his peers and is the most "normal" of the kildren.

Midori despises Tokino's escapades, as she cannot ignore the lack of meaningfulness of her life and live like him. She does not accept her fate and wrestles with it instead, that is why she speaks to Kannami as if she herself were not kildren. She loses control of her feelings and shoots at Kusanagi, whom she despises, apparently for having a true love affair and a child, which she does not, and for having killed Jinroh (maybe she was also in love with him.)

Kusanagi also scorns Tokino's hedonistic ways and is desperate about her situation. However, she hides this with her role as a superior and wears a mask of equanimity. Because over her skills at aerial combat and her retirement from flying combat missions, she has not been killed in action, at least not for a very long time (8 years.) Her ongoing relationship with Kannami and his various reincarnations makes her feel even more desperate. Even though having a child with him makes her more like a non-kildren human and is considered very unusual if not unique, having a daughter but never physically growing up herself makes her even more aware of her plight. She has killed Kannami's former incarnation Jinroh, who may be the father of her child, at his request, or so she says, and wishes to be killed herself. Only when drunk she paints her lips red and gives in to her feelings in order to escape reality, if only for a moment.

Kannami encounters his fate with genuine equanimity. He does not question the purpose of his role as a combat pilot, which he considers to be a job like any other, and when he learns about the true nature of the kildren from Midori, this changes nothing about his stance. He seems to differ in that from his former incarnation Jinroh, which is sort of strange, considering they are clones. His solution for the dilemma of the kildrens' ever-repeating life is found in this quote: "Even on the same old road, you can tread new ground. Even if it's the same old road, the scenery isn't the same. Can't things just be that way?" From that, Kannami seems to draw a positive attitude towards life.
So when Kusanagi tries to kill herself, he prevents her from doing so. He does truly love her, and his equinamity seems to be shaken when he realizes the extent of her desperation. Thus he continues the quote, visualizing shooting Kusanagi: "Or is it no good, because that's all it is?" He does seem to believe that escape from the kildren dilemma is possible when he tells Kusanagi to "live on until we can change something." The solution may be to kill the Teacher, but we do not learn if this truly is so. Kannami seems to be wrestling with himself, but then makes up his mind: "I will kill my father." But when he does get the chance (I think he does?) he does not shoot him. It is unclear why. Maybe kildren are programmed not to kill the Teacher.

All in all a fascinating movie for someone who can accept the premise, and should definitely be watched at least twice. Observing the characters, and especially Kusanagi knowing their situation, is truly heart-wrenching. I would love to read the books, but unfortunately they have not been translated into English (yet.)