About the knife sheath, it can be carried horizontally on your belt on the back. The other options you see: space for a fire steel, when opening with the snap button it flips open automaticly because of the elastic, it can also be carried next to your leg with a dangler and using the leather cord around your leg to keep it steady, ...
The edge is really smooth, except my pciture doesn't show that.. I'm a leather worker, not a really good photographer
Thanks for the comment btw
Maybe you can have a better look at the edge on this pic: