Bad teacher

I don't like this film much, and it's all about the plot. I don't like this screenplay. There's Elizabeth (Cameron Diaz of course) who is a teacher but left the school to marry a rich guy. When the engagement is broken by his wise mother, she's forced to go back to work. She cares nothing about her students, her school or anything else actually. She's only interested in men with money to get one for herself. She turns down Russell (Jason Segel) because he's only a gym teacher, and she focuses herself on the new teacher Scott (Justin Timberlake) who apparently comes from a rich family. I don't remember how.
She makes herself an antagonist out of Amy Squirrel (funny, she looks just like a cute little squirrel - played by Lucy Punch). Amy is her complete opposite, and she's interested in Scott too.
Elizabeth thinks that to catch a rich husband she needs bigger breasts, but the surgery would cost a lot of money, so she goes frenzy doing anything to get her hands on some money, and every bit of it she puts into a big jar with New Tits written on it.
She washes cars wearing little and moving like a porn fantasy. She takes bribes from parents, promising them to take particular care of their kid, while actually she doesn't even know their names, and is too bored or tired from a wild night to waste her time teaching them anything. She simply puts a dvd on, but at least I had to give her this: she only chooses movies related, in some way, to school, like Scream for example.
Still, after knowing that the best class to score at the state exams will receive a money prize, she starts teaching them wanting them to learn fast, and when she realises they'll never be number one she steals a copy of the test in order to cheat!  She's not a good example, she comes to school with a  hangover, uses drugs just outside and even steals an ornament at a student's house to give it to the principal and make her look good in his eyes. Amy is totally against her because she knows she kept for herself money she should have given to the school, and that she uses drugs. When she learns that Elizabeth cheated at the exams (because she did, and she won) Amy tries to have her thrown out but Elizabeth manages to turn the events in her favor and against Amy. Of course she's funnier than petulant Amy, but still Amy was right all along, so it doesn't seem really right that Elizabeth should win so completely. At the end, Elizabeth is a respected teacher in a relationship with Russell (of course, there were no doubts about this from the start), while Amy breaks up with Scott because Elizabeth made her believe he betrayed her, while truth is there was something between them that took place in the same hotel room, but they never unzipped... it was all a stupid, embarassing scene, not funny just boring. Amy also loses her job and will get transferred to a difficult school.
What's more, things are very badly developed because one scene she doesn't care if a boy is humiliated in front of everybody at school, next thing you know she's helping him. Why? What changed? Apparently nothing, it's nonsense. Apparently she realises she's been really superficial, and this too is nonsense. What does this mean, that she didn't know? Come on, that's stupid, there is no reason in this film why she should change her mind and stop going after rich men. It wouldn't have been difficult to create some reason for that and for her sudden interest in the students, but thing is there was no reason at all in here. It was utter nonsense and to me not even all that funny. Cameron Diaz also looked much better at the end without all that fire-red lipstick on: I guess that represented her rich-men-hunter persona, so at the end with Russell she didn't need it anymore. Good, it didn't suit her at all, she doesn't need any masks.