It's amazingly hard to find information on that model. Anywhere your notebook is mentioned, they just say it has a 1.2Ghz celeron, no info regarding the ~1.5GHz issue. Where did you find the 1.2~1.5 ghz statement?
As I did some research, I can tell you what i think about that notebook now. It's basicly a small bit more powerful than a netbook and has a bigger display than netbooks. Overall experience in win 7 is probably almost the same as with any netbook with 1.6 GHz Atom CPU.
Looking at your cpu history, i can't see anything abnormal. You have a slow cpu, that's why there are so many huge spikes when working. Don't want to sound offending, but either get used to it or pick up a faster notebook. At least cpu usage doesn't stay at 100% all the time

Using the tutorial i linked earlier won't change your situation very much. Maybe your notebook would be a little more responsive, especially when you turn all the eye candy off. But a turtle will never be as fast as a horse.