ICAO allow in cases where an aircraft is not crossing an international border, they can speak the local lingo. I know this is not the case in France IE AFR and TSC frequently speak French. Unacceptable. As for "Line up and wait" , it's clear, and takes less time to say. When your freq is busy this is an asset, that's why I personally prefer it
So what is the clearance when the tower needs an immediate takeoff for traffic? "Line up and wait, cleared for immediate takeoff, no delay?"
Is is possible that those operating in other parts of the world have no appreciation of how hard US ATCO's are pushing traffic over here?