You can re-calibrate all brushes at once by going to Edit>Preferences>Brush Tracking or just CTRL+Shift+,. When you do this the changes affect all the brushes instead of just one. You don't have to re-calibrate your brushes every time, painter saves the last re-calibration you did.
Ha i see you are enjoying painter's inking. I recommend you try the Smooth Camel brush. You'll love it. That's what i use.
My scratch board shows just the blue colour dots. I think his is the Mac's.
Yeah Painter is an amazing piece of software. I would be the defacto digital artists tool if only they are able to clean it up a bit. As cool as painter is i don't use it when i have close deadlines or in a bad mood.