Orgers,
Repetitive strain injury is real and important.
One thing that you can do is to ensure that you have a keyboard that
has modifier keys on both sides. You should pound a new habit into
your cerebellum: use two hands.
For example, c-c c-o should look like this:
r hand presses ctrl
l hand presses c
let go
l hand presses ctrl
r hand presses o
let go
This is obviously inefficient, but it is the correct thing.
Ideally, the most important c-c and c-x operations would be on the
lhs. That way, you can hold down ctrl and press the two keys.
Many (maybe even most) will find this idea strange. But I urge all of
you to try it for a few months.