Several times in Iron Man 2 Tony Stark mentions that he doesn’t like it when people hand things to him and prefers that they just set whatever it is down. Was this relevant to the plot, or any sort of callback to the first movie? Or is it just to characterize him as a slightly eccentric billionaire?
I haven’t seen the movie yet, but I’m the same way. The main reason is that I’ve been in the restaurant business for nearly 27 years, and in that business there is a lot of passing things from one person to another. Experience has shown me that the most likely time something will get dropped is when it’s being handed directly from one person to another - the person doing the handing over accidentally lets go before the other person has a firm grip. And when the things being passed include hot food and sharp knives, that can lead to injury. So the preferred method of passing things is I set it down in front of you, and then you pick it up.
I can see the same principle being a good idea in Tony Stark’s line of work.
I thought it was a way to give him a hint of Howard Hughes-style weirdness.
I thought he was paranoid about being exposed to germs because his immune system was compromised by the palladium poisoning.
I think this is the most likely answer. Being questioned by those senators was right out of Hughes’ life (and the Aviator biopic) too.