Amir,
Bugs are already reported for some of these issues,
but the basic
question is - why reimplement it all in the first place? Why not use
what the browsers offer as much as possible?
there is actually a possibility that a very atypical way to use
contenteditable might make a cameo appearance as a thin surface layer to
help with input stuff (see VisualEditor/contentEditable for a
prototype). The atypical bit mostly stems from the need to avoid the
many problems current contenteditable implementations have, and the
desire to support a good user experience while editing *wiki* content.
In any case, the editor team is currently hard at work on exactly these
problems, as is described in
https://www.mediawiki.org/wiki/Visual_editor/Phase_2.
https://www.mediawiki.org/wiki/Visual_editor/Bidirectional_text_requirements
and Visual editor/Internationalization requirements are helping a lot in
this work, thank you for documenting these things!
Gabriel
(who knows very little about the horrors of contenteditable
implementations..)