Yes, we've known (and been enraged by) the font-size changing bug as well. Not sure what the deal is with the beachball you've gotten intermittently, but there are a few updates in the pipe (waiting on App store review process). One of them allows you to resize the left column to your heart's delight, as well as fixing the strange styling issues in the message box when pasting rich-text. After the update, you should no longer be able to inadvertently change the style of text presented in the message box.