I will ask the question on the blender forum. Maybe they know more about there. I saw that there is always reference to some python script when rolling over the shortcuts, although I do not know anything about it, I though you might lighten my path.
Thank you for your reply. The option ’emulate 3 button mouse’ is not giving me the possibility to do the movements I discribed in my question but holding the left mouse + ALT, so that means that I loose the possibility to select with the left mouse.