procedure for precise cutting by ear

In order to do precise cut, i would like to be able:
a) select an audio region
b) create 4 keyboard shortcuts: two for moving left edge of the audio selection to left or rght, two for moving right edge of the audio selection to left or right. I want edges moving with steps of 5ms.
c) i would like to have a cycle listening of the selection in order to listen to the audio file in order to choose where i want precise cutting both in left edge and right edge.

How could i do it? Can you give me the detailed procedure?

Alessandro, thanks!