Here is a semi complete story:
Took it to Alphawerx for over 3 weeks and Alphawerx inspected it thoroughly plus test drove it at least 3 times. Changed rotors, sanded brake pads, new tires, and balanced and aligned wheels but did not solve the problem. Actually, Darren balanced the wheels at least 3 times. He even run it at many speeds so many different times while hoisted it up to see if it's the main drive shaft. But no problem was found until then. Finally, I was told it is the driver side drive shaft so I had it repaired but the car still shakes.
Took it to RMP Motors and they test drove the car and inspected the wheels and balanced the tires (4th times in 2 months!) but the shake is still there. I was advised to change the thrust arms because the steering trembles when braking and hitting a pothole. Rocco did not say the thrust arms are the cause of the shake, but since I have to change them anyway then I will wait to see if the shake goes away after changing the thrust arms.