The Marco/Mario thing could have been a typographical error on his sheet. I'll have to watch the speech tonight, but maybe that was in the preliminary introductions -- the part where the candidate has to acknowledge all the elected officials that show up.
They don't get to practice that, because nobody knows who is showing up, so they get that written down at the last minute, and they have to read it or recite it from memory. It's easy to see how someone could scribble down "marco" in a way that looked like "mario".
As to the other phrase, Mitt didn't say it was a liberation phrase. He specifically said it was the Dictator's phrase, but he argued that it better represented freedom than communism. He might be right, he might be wrong, but it was a compelling suggestion, and I do like how he's willing to make statements like this without regard to whether others agree with him.
I wonder if Representative Rene Garcia is backing a different candidate, and therefore had a purpose in attacking Romney?
President Bush, as a candidate in 2000, called a radio talk show host in Pittsburgh whose name was Fred, "Frank" throughout an interview.
Fred didn't correct him at the time and, of course, made (relatively gentle) fun of him afterwards.
Flubbing a guy's name is typical for candidates, they get a list that they read from a sheet and they see so many. And you'll notice they aren't stupid enough to do any "my good friend" nonsense.