3) There is no any small length limit for security code, so it can be qwertyuiopasdfghjklzxcvbnm... Twice or triple. Even 200 characters are ok. 5) Devicelock 'Numpad' view is a standard feature available on any N9, just enter lock code which contains numbers (0123456789) only (locked device will look similar to PIN query, for example). It is not possible to switch to full VKB qwerty mode as it is not needed here.