I'm sure it was just an oversight, but you really did mean to start your reply with some kind of "thank you", right?
I feel that the <CLEAR> button is "best used" for exactly what it does now.

The package is open-source, and an easy-to-edit python script. If you are of the opinion that something is a "must-have", then make the change. Personally, I don't want to clear numbers from the history list (and that's actually more difficult than it seems). The history list is stored in a file: /home/user/.gcdialerhist, which lists the number called and a timestamp. "Clearing" a number would mean re-writing that file, rather than just appending each successively called number.

One alternative that just came to mind would be to enable a new button that only appears after a successful call. That button would allow the user to append the current number to the history list. Frankly, I really don't like that as much as the current model, but I'd consider it.

As far as the <BACK> button, that's a "backspace" key. Without that, pressing the wrong key at the end of entering a 10 digit phone number would require starting over....

Feel free to play with the GUI (built with glade-3) and the python script. If you really want the ability to remove numbers from the history list, I'd suggest dedicating another button (or a menu item) to that function. I'd be happy to accept code submissions with any modifications.

Of course, you can always edit (or remove) the history file itself.

You're welcome.