My 400ex thumb throttle was shaking when I was revving in neutral and it felt like the stroker was unaligned but when I rode it around it was fine. What is this all about?

Would a high bend handlebar get rid of my handlebar vibration too since they are low?

Also, my thumb throttle has a short space that doesnt respond when you first rev in the first half inch of couple cm's. Whats this problem?

 

Could try taking it apart and cleaning and lubing it?