After a sudden flash of brilliance, I have come to the conclusion that every keyboard should have a 'Forward!' key to complement the Backspace key. It would be on the left-hand side of the keyboard, directly across the number-line from the Backspace key.
*The Plus and Minus keys could be moved to replace the buttons for Page Up and Page Down, which could be implemented as functions on the up and down arrow keys.
*The number keys would be shifted so that 0 was right next to Backspace, making room for Forward!
*The Forward! key would function as an alternative to the spacebar, and it could also be used to return to a page which you had just gone back from, much in the way that the Backspace key can be used to return to a previous page.
*Pressing Shift and Forward! at the same time would work in the same way as a left-button mouse click. Control and Forward! would produce an effect identical to that of pressing the right mouse button.
That is all. Perhaps I shall construct a diagram of the ideal keyboard to post later on!