If I could remove a key from a full keyboard, it would be Num lock. Why does it exist? I can't think of any situation where you have a full num pad and don't want to use it.
I use it to check does OS kernel respond to a keyboard. When kernel is dead LED wouldn't switch state. I cannot use CapsLock, because I have no, I remapped it to a compose. I cannot use ScrollLock LED, because it reflects a chosen keyboard layout, and I believe it needs more than just healthy kernel to switch LED. But I never messed with NumLock, because I see no reason.
I'd remove Insert key. I regularly hit it by accident and I see no reason for insert-mode to exist except to annoy me.
I’m pretty happy we kept a ton of “dead” keys as they offer a flurry of options for more modifiers and shortcuts. The same way most people probably only use one of the Shift key, one of the Cmd key, etc. but it would be a shame to remove them. I’d see Num lock under the same light.
I went with Apple’s “international” layout just to have more keys to map.
