So, the surface is to coarse on the stone to start use it on my razor then, hmm...

With a 600 grit paper (wet or dry), i get a decent surface to start honing. I guess it that is done for both 4000 and 8000 grit sides? Is a lead pencil ok to make the grid on the stone? I guess the lead is the softest and shows the surface best while preparing it.

I was thinking of putting the sandpaper on a plane surface and then, with light pressure, rub the stone circular until the grid is gone. Should i continue with a fine sandpaper after that or is it enough?

When you used a piece of glass, what kind of glass did you have? I'm a bit worried i will get "hills and valleys" on the stone when i start preparing it.

Regards,

Rikard