Lexus ES330 Throttle Body Valve Settings?

[ml30306]

I own a 2004 Lexus ES330. When I cold-start the car it will immediately rev up to around 2000 rpm before settling around 1400 briefly and then going to under 1000.

Is this normal? I checked the throttle body valve and noticed that when the car is stopped the valve does not fully close. I have seen some discussions on other sites where some argue that a fuel injected engine throttle body valve should or should not be fully closed.

Here my questions:
1. Should the throttle body valve be fully closed or not?
2. If yes, can it be adjusted via the main on board computerized settings?
3. Should my car rev that high on a cold start? I also noticed that the car experiences a pretty high acceleration when not even stepping on the gas, I feel like when breaking I am really having to hold the car back from taking off on its own.