The iOS7 upgrade is either installed on a device or it's not. Apple doesn't push a copy to the iDevices and have it sit their until you want to install it or not. What Apple does do it push a notification to your devices letting you know an upgrade is available by putting a badge on the "Settings" app.
Yeah, they do. You can choose not to verify and install immediately after downloading it. Then when you go to verify, it won’t have to redownload.
Apple doesn’t download in the background, but you can download without installing.
They dont automaticall install any os upgrade, you will be asked if you check in software update before anything is installed and even then you have to push the button to do so.
They did not automatically install anything. I didn't say that. They did, however, download it to my devices without me requesting it. Check out this screenshot, showing the update as "downloaded". (maybe they have me confused with John McCain )
I clicked the install button right after taking the screenshot and it went straight to "verifying update", no internet activity showing on my DSL modem.