It appears you have never ever configured a notebook for secure use environment, I assure they can be configured to download only what you want them to from a source you specify.
Sure they can. You can pay technicians to make sure they are locked down and patched in the same way that iPads are locked down out of the box.
16GB less operating system, less applications, less multi-media content, less all required texts and plus references works and less student created content, shrinks to nothing pretty fast.
Do you actually own an iPad? Because I can assure you that's not the case. Movies will fill it up, as will the entire MP3 collection that some teenage kid has ripped off. But there's no chance of making a dent on it with a years worth of educational materials.
Plus you can protect the screen and you have a keyboard whilst retaining a full sized screen.
You like laptops. I get it. So do I. But they are not the best thing for school level education. The educational content available for the iPad is endless and far outdoes what's available for PCs. The great thing is that kids use direct manipulation through the touch screen. There is no level of indirectness as their is with using a mouse and keyboard to control software.
The drive with computerising schools to to get students to create content not bloody mindlessly consume it, just to drive corporate profits.
You're really playing through your biases now aren't you. You do realise those laptops you are suggesting cost money. And in most cases the content creation software you refer to is Microsoft Office.
Probably in your mind it's Linux. But that's not the real world of school education in most cases.
As to creating content, school has always had more consumption than creation. What do you think text books are? Stuff done by the teacher on blackboards, whiteboards, and these days projector screens? Thats consumption too. Of course they have to do tests based on that content. For which the iPad is a better option than a laptop. And any artwork or design work is better done with an iPad than a laptop (of course in actual art classes they'll mostly use paper).
At some point they'll be writing of course. And there, finally you do have something that the laptop is better for. But school writing tops out at about 500 words. And kids don't have a problem with typing on a screen.