Your english is very good.

I'm not an expert on NSR150's but I think the RC valve movement at a high idle sounds like the NSR250 "high" position check, for setting the valve position. Therefore, not something to worry about. This feature allows you to find the high setting position of the RC valve servo-motor, without having to take the engine to full revs whilst sat in the garage in neutral.

I think the idle, (tickover), speed of the engine just needs a slight adjustment. This is usually by turning a screw on the carb, or by turning a thumbwheel attached by a cable on the MC21 NSR250.
If you back the idle speed down a little at a time, you should find that eventually the problem will will be cured.

By the way, the idle adjustment screw will affect the carburettor slide rest position.
There is another screw on the carb which affects the idle mixture strength. The pilot air bleed screw. This is normally situated at the back of the carb, usually it is screwed in fully until it lightly seats, then backed off usually 1.5 to 2 turns out. You need to make sure that you adjust the right screw.
Happily, you shouldn't be able to do any damage to the engine by adjusting either screw incorrectly, just cause inconvenience mainly.

If you are not sure about what to do, ask someone experienced to show you how. Or take it to a shop.