My guess for the edge cuts is that you are not reversing direction quick enough while you are flipping the razor at the end of your stroke. That leads to a slight stop or even slight backwards movement of the edge on the strop resulting in cuts. Been there and done that too.

Check and see if there are rough or sharp edges where decorative notches are on your Bismarck. That could very be the problem. I have had a burr on the edge leave fine scratches in the strop also. Maybe check the edge with a loupe too.

The only pressure you need while stropping is enough to keep the spine and edge in contact while just skimming along the leather.

Bob