Games Support

I love this program. I hope this is the right place for suggestions. Without bloating the program too much it would be great to:

1) Be able to use alternate keys for entering "possible numbers" (PN) (Shift+1..Shift+9). I would like to be able to use either the keypad 1..9 to be PNs, or even QWEASDZXC as 789456123 (mimicking numpad) or QWERTYUIO as 123456789 (the row just below 123456789). That way I wouldn't need that infernal Shift key pressed. Alternatively, allow CAPSLOCK on to signal PNs.
2) Undo last action(s) (e.g., Alt+Z or "U").
3) Allow Branching by Saving current board and Restoring to that state

this is the second time this has happened
game puts 2 of the same number in the same row
http://pbase.com/image/65586767.jpg

I love how UPXing Sudoku Portable allows OpenOffice.org to run faster (Says so on the support page);)

Is the "Impossible" level of play possible to solve without guessing? I don't see any listing of what the levels mean. In my view, if you have to make a guess and follow it through to see if it works, it is no longer a logic puzzle. I have run across this type and don't want to waste my time unless it is solvable without guessing. Thanks.