17 years later . . . Mixed Feelings

I couldn't disagree more. In fact, I must ask if you truly paying attention. At six episodes, Gunbuster covers a remarkable amount of ground in character development. Noriko develops in a believable way. Were you expecting her to go from cry-baby to Rambo? Let's address your complaint individually.

"Noriko never really goes anywhere character-wise"

Your kidding, right? Look at her in episode one. Could you see this character make the sacrifice she does in episode six as is? No way. In one, she's unmotivated, clumsy, and very dependant on others. The whole show focuses on her overcoming this.

"even after defeating the alien horde, she still makes assinine remarks about graduating high school."

So, she should act human any more? Just because she's overcome her weaknesses doesn't change her personality. Wouldn't you be bewildered to graduate high school, practically alone, after a long, sordid battle in space that changed everthing for you, when you're back on earth, but it's years later there, and it's only been months for you? A key theme in that episode was reconciling her current and past self.

"Then, for no reason, she's the one who bitch-slaps Kazumi into snapping out of her Coach funk."

Wow, you must've taken that soda break during the scene between her and coach. Coach explains fully that she is the stronger one. While she had the clumsy start, her potential and experiences allowed her to set aside her personal feelings, nay, let them motivate her, to carry out the greater good. Kazumi, while talented and professionally disciplined, lacked such strength oer emotion. She let it be a crutch rather than a torch, as Noriko did. Coack understood this, and she didn't believe it herself until the time came. You may have noticed that it's the only time she calls her "Kazumi" as well. They're roles had essentially reversed. The development in the previous four episodes supports this.

"And the battles are sooooo hurried"

Actually, they're perfect. When one has about three hours to tell a tale, one uses it wisely. The battles were part of telling the story, not the story. You want mindless action, watch Dragonball Z.

"I'm inclined to believe that they just knew they wanted teenage boobies, time dilation, giant robots, and insect aliens and then made up the rest as they went along"

Riiiiighttt. That explains how they managed to blend epic story, character development, action, humor, and drama about a girl learning to realise her true potential, coming to grips with sacrifice for the greater good, all while using time dilation to great dramatic effect, with plenty of homages to classic super mecha shows and spectacular animation, acting, and music, all in a mere three hour package. Talk about poor planning.

Gunbuster is like the retarded sibling of Evangelion, no reason to watch it more than once to see where certain shots or plot elements originated

“and I never saw the final episodes”

Now’s your chance. Discotek is releasing a new blu-ray version. You can pick up the whole OAV series for less than the $50 you originally spent for just 2 eps.