keyboard short cuts make the workflow very fast indeed but they are sometimes hard to memorize unless they are a standar(ctl+z for exemple)
and sometimes can be irrelevant when a mouse click is mandatory as a complement.(think about the shift click to ignore the axis on the manipulator).
so a solution that i found very clever is to make a keyboard shortcut work on the maximum different every day situations depending on contexte.
and then ask the user to remenber (if he wants) another keyboard shortcut that can be used also to do different things(priority to most used tools) depending on contexte.
here is a simple exemple that i found to be very clever.
{F106695}
another thing that i'm not the first to talk about.is the consistency of manipulations between working environement.regarding the blender experimental 2012 wich i found
the closest one to what should be fine.the same manipulations concept of click and drag on the viewport should be ported to the graph editor .or the user will feel
he is switching softwares inside the same software.and usualy this breaks harshly the interst of a new user.