If another bank attempted to buy us during the year, should the letters to shareholders be included in the public file?

I would recommend talking to your examiner about this.

They are letters to the shareholders, not to the bank itself. If all letters were sent to the home addresses of the shareholders, than I do not think you would include them.

If copies where sent to anyone at any of the bank's addresses, than maybe.

But this is strictly my opinion; I have nothing solid to base this opinion on.

Only include letters relating to your bank's CRA performance in your bank's public file.

Don't clutter it up with nonessential letters.