1739 Of Off

I've mentioned before how words come at a premium in the radio business, time being short and all. So, as a radio person, I notice extra words a lot.
Like when someone says, "His riches were the end result of hard work." Do we really need to say "end"? Isn't it pretty much implied by the word "result"? Yes, yes, I know you can have intermediate results. But all results are ends so it just seems redundant. Like saying, "The start of the beginning." A lot of extra additional verbiage.
Or how about the two words together so many of us use, "off of." It's 20% off of the price. Take the Smith Street Exit off of I-5. He ate the icing right off of the cake.
Wrong. You can just say off. In these instances "off" is a preposition in it's own right. So you don't need another preposition in a post position.
"Off" is versatile. It can be an adverb. Like when you say, "The party is a week off." Or, "He's going to drive off." But it instantly transforms to a preposition when you say, "He's going to drive off a cliff."
"Off" can be also used as an imperative interjection, as in "Off with his head" Or it can be used as an adjective, as in, "The wedding is off." Or, "He stood with his shoes off."
My favorite is when you actually do need a preposition to clarify that "off" is not a preposition. The antithetical word to off, "on". Compare and contrast: "He went off grammar for good," to "He went off on his grammar teacher."
Let's hope he doesn't get angry at a power controlling device. The end result would be he went off on the on-off switch.
America ya gotta love it.