For example, if you say that “feed” isn’t a real word because there is a better way to say “issued someone a fee,” but the real word is “feed” as in “to provide with nourishment,” what would that error in judgment be called?
Do you mean that used-car salesman dialect where they’re “efforting the ask for the spend” and similar embarrassments?
I don’t really understand your question. Feed meaning “to offer sustenance” has a different etymology than the noun fee meaning “amount paid.” While virtually any noun in the language can be made a verb, it seems unnecessary in this case since to charge is available and already expresses this meaning.
I think you’re essentially confusing homonyms (or forgetting one of them). A homonym is “One of two or more words that have the same sound and often the same spelling but differ in meaning, such as bank (embankment) and bank (place where money is kept).”
Also, it’s kind of funny that “feed” as in “issued someone a fee” isn’t an accepted word when “fine” is (which is also a homonym :)