Sadly, we built an editor that solved all of these problems but we got virtually any traction in terms of sales (it was $99). Was considering re-releasing it as a WYSIWYG markdown editor because I think the market is more clear.

I hear you with respect to the difficulty in getting it right. Sometimes we would have a few lines of code and then 50 lines describing why the code was necessary in order to get around weird edge case behavior in one version of one browser.