A quick comment on your question about the hands position of the SS agents. I have worked as a bodyguard in Japan for a long time. This was one of the first lessons I received from people I was working with: when escorting the principal through a crowd of people who are expecting him and engaging in contact with him (shaking hands, asking for an autograph, etc.), you hold your hands somewhere around the level of your lower ribs

Now everytime you see the president or a big wig out with a secret service detail, you’ll notice their hands are always like this.  click through for a dozen more examples!

via US Secret Service Hands Ready.