So far climbing appears easy enough, on the other end once I am up on the top I find no way to climb back down. Jumping is often suicide, isn’t there an option/command to climb down?
Climbing down is even easier!
Just jump down turned with your face to the wall/rock and press (several time just to be safe) SPACEBAR. Your char will just slide down the wall/rock like a pro 
This way you can climb down even the biggest cliffs!
You can climb down, it’s the same as up only in reverse.
But just jump and grab on the ledge, it’s far faster