1) since day one, the instrument cluster illumination at full brightness still leaves the temp/radio/other center console switches dimly light.

Do you have the Bose Radio. The brightness can be configured within the menu options. Never had any problems with brightness of the other things.

2) Both the drivers(especially this one) and the passenger windows do not rollup normally. The electric motor is very slow in closing the window.

Our 2001 ML430 also has very slow windows. I just thought it was the design. I'll have to check out another unit to see if there's a difference.