The reason Apple doesn't include a proper delete key is because they don't think it is required, and most users don't really care about it, as the Backspace key in OS X works as a Delete key anyway. The CTRL + Backspace key works as a usual Delete key as well.
Of course Apple are going to make some changes that users don't like, but they won't add features just because 10% of their customers want it while the rest either don't care or haven't noticed (i.e. new users to computers). An example is, without notice, changing the orientation lock switch in iOS 4 to a mute switch and a lot of customers did not like that change, and Apple heard thaat loud and clear and in a future software update Apple added an option to change the mute switch to an lock orientation switch.
So I am sure if enough customers reported about the lack of repeated characters they will do something about it, such as allowing users to change this default setting in System Preferences. The same for scrolling speed, if a lot of customers reported about it to Apple. So, as others have said, your best advice is to send feedback to Apple. They make out they are arrogant, but they aren't, and they will listen to customers if enough of their customers report on it. They do what they do for customers, as well as any other company.