Joe – Of course you are supposed to try to correct it, if you realize your mistake, but it is not in order to TELL something to HKB”H. But if you are sincerely trying to connect and somehow the word is a difficult one for your lips and tongue and teeth to pronounce exactly, I don’t believe you will be punished for it. I think the seforim hakedoshim that you are referring to are speaking to the people who are on the level to say these words without difficulty and are nonetheless not pronouncing the proper words.
Are you of the opinion that a English-speaking (or whatever other language) BT should never attempt to daven or bentsch in loshon hakodesh because he might mispronounce words?