I'm all in favor of finding workable command shortcuts. Unfortunately, I don't think these changes will work for Macs as Ctrl-E and Ctrl-Delete already have other behaviors bound to them in OSX. Ctrl-E jumps the insert caret to the end of the current line. Ctrl-Delete deletes the currently selected text.

I'm suspecting we need a bit more research on good approaches to keyboard shortcuts in web apps.

I have left the original bindings to Meta keys intact. The code is if (event.metaKey || event.ctrlKey) so that Meta+e continues to work on Unix only and you won't have to press Ctrl+e
Edit : oh ok I feel dumb, you have probably meant this code would swallow the original text editing features, I agree.

But pressing Ctrl-E on OSX will behave incorrectly with this change. It should not toggle the edit/preview mode.