With the original macros my BC 5.1 showed different Python error message during startup and these macros weren't available in the menu bar.
I checked the source code of some of the macros that came with the BC 5.1 installation and there were some comments that with BC5.1 some functions have moved to different dll's. I changed the source code accordingly so that my BC is now starting without error messages and I can start all of the macros above.
But meanwhile I discovered that "Surface to Points" creates an ASCII error message during runtime and "Surface to Grid" complains about an invalid file name in the surface selection drop down field.
I'll have to look into that.
I removed "surface to grid" from initial post.
The other macros from my post run in BC 5.1.