Well if we ever meet up in real life, Boxy, I will address you as Chair, just be mischevious.
I still do not see the root of your objection though. Things change. Cultures change. Language changes. All the time.
And there is nothing intrinsically more unwieldy in using the term "chair" or "chairperson" than the term "chairman".
And why on earth would you need to have the extra Mr. when describing the Mayor? What on earth impels you to support the entirely superfluous Mr except tradition and the reluctance to accept change?
This might sound confrontational - I do not mean it to be, but I am genuinely confounded by the reasoning behind rejecting terms like "chair" etc, and bewildered by the need to retain "Mr.Mayor" when referring to the Mayor, be it male or female...