That's interesting,
Pitch. I really like the change with Gandalf. And that recording is just priceless!
In the Russian translation, Sam addresses most people defferentially. I believe (and I'm saying from memmory) that the only two people that he called by the familiar form were Hob Heyward and Gollum: the former as a friend and the latter by looking down on him. As hard as I try, I don't remember how he addressed Rosie. She addressed him in a familiar way for sure.
It seems to me, though, that Frodo was trying to convince Sam that he's not a servant but a friend to him. And Sam resisted believing that with all his might. I find it especially visible when Frodo speaks to Sam using familiar terms, and Sam replies defferentially.
Like in the German translation, Frodo addresses Maggot defferentially.
That Feanor quote is truly smashing!
I wonder how he was still alive after that!