You should keep speedstep enable, it just drops the CPU speed/volts down (saves leccy) as its not required to run at full whack, and when it is it will automatically jump to 2.4GHz (i.e in games).
I wouldn't worry about the ram either as your memory at 800MHz (DDR 400) is actually running faster than your CPU requires, and you could even overclock your CPU quite a bit without needing faster memory.