Hi,
I think perhaps some underlying porperties of mobile device environments are getting overlooked in this discussion. Javascript works great if you have "beefy" CPUs, i.e. not ARM chips, and large amounts of memory available. Feature rich, responsive UIs run into trouble on ARM chips on mobile devices so they have to be pared back considerably to give a reasonable user experience.
Here's a couple of articles on the subject: http://sealedabstract.com/rants/why-mobile-web-apps-are-slow/
And a response, with clarifications: http://www.codenameone.com/3/post/2013/07/why-mobile-web-is-slow.html
In short, if you want a "word processor-like" editor for Moodle on mobile devices, use a native word processor app and then copy and paste it into Moodle as HTML code.
Since Moodle already uses Javascript UIs extensively for navigation, etc., it's well worth considering dedicated UIs for mobile devices or even going the native app route. Perhaps Moodle could autodetect mobile devices and simply offer a paired down version of whichever text editor/formatter you like with easy intuitive copy and paste functions built in?
Re: tablets, "Turns out people want things that are the size of a laptop to work as well as a laptop." - symbolset, via /.
Just my €0.02!