For the most part, it's simply a matter of determining whether the particular idiosyncrasies of a person's speech are too archaic to be understood by a contemporary audience--in this case, alterations need to occur to properly convey the intended meaning or emotion. In the case of more vernacular colloquialisms expressed through poor grammar, however, I give leniency, considering the nature of the blog and the importance of maintaining the tone of each individual's voice from piece to piece.