FFS, why the hell have they decided to put INS as an Fn function on an oversized DEL key?
Ins switches between 'insert' mode, where characters are added where you type, to 'replace' mode, where when you type characters in the middle of a line, each character replaces the character after the cursor.
This is rarely used. If people want to replace some text with other text, they can select the text they wish to replace with the mouse before typing - and now the replacement doesn't have to be the same length as what it is replacing.
So it's a key that is hardly ever used now, and it causes trouble when hit by accident. Thus, I can almost see this as a good idea.
The way
my mind works, though, I don't believe in ever getting rid of or doing without a key. Yet I realize the need to apply restraint to my preferences. So I've come up with this layout:
It has Windows keys. It has extra keys on the cursor cluster and the numpad, for 122-key keyboard emulation (the one on the numpad is needed for use as a Mac keyboard, too). It has the 102nd International key, to the left of the left shift, in case one wishes to use an international layout (and also for 122-key keyboard emulation). And it has four keys over the numeric pad, to be used for the Sun keyboard's version of ACPI keys.
And there are a couple more extra keys, usable as Fn keys, so that the keyboard doesn't need to be made bigger, but the large groups of extra keys found on the Sun keyboard and the 122-key keyboard can be emulated as shifts.
So I can avoid ever leaving anything out, even the Scroll Lock key.
Rather than a non-remappable key, though, some method of changing layouts would have to be discreetly hidden.
EDIT: But this keyboard has a fatal flaw! It's impossible to dye the Esc key red! Ah, well, the color scheme can always be changed, perhaps by switching white on black for black on white.
EDIT: I've changed the control character keys from black on white to a light cream color since the post was originally written.
EDIT: This image has been changed again. Only one key is now added between Alt and Ctrl on both sides, and the keyboard is no longer made slightly less wide than the original 101-key keyboard.