Maybe this will clear some things up, or maybe not...
Pennsylvania v. Mimms, 434 US 106(1977)-The driver can be ordered out of a vehicle, without suspicion, on routine traffic stops. The officer's safety greatly outweighs the inconvenience to the driver.
This means I can get you out and pat you down for weapons before I ask you any questions.
Maryland v. Wilson, 519 US 408(1997)-This case applied the Mimms case to the passengers. The same legitimate reasons an officer has to order the driver from the vehicle also applies to the passengers.
This means I can get everyone else out and pat them down also before I ask you any questions.
US v. Rice, No. 06-5138 (10 Cir. 2007)-[Officer] Weakley did not need reasonable suspicion to request identification from Rice [driver], run a background check on him, or remove Rice or any other passenger from the car. These actions are fully justified by officer safety concerns no matter how innocuous the traffic violation and need not be supported by additional reasonable suspicion.
This case re-affirmed the previous cases.
Also there is another case that I couldn't find that allows me to "pat down" the interior of a vehicle, meaning anywhere that any occupant could reasonably be expected to reach while in the vehicle, before allowing the occupants back in the vehicle.
Do I do these things on every traffic stop? No.
Could I do these things on every traffic stop? Absolutely.
If you appear more nervous than the average person does, or you give me conflicting statements, or I can articulate a reasonable suspicion based on time/place/circumstances you better believe I am going to do these things. My choice to do these things is based on the totality of the circumstances at that moment.