> Yes it can be great, but I think this take a lot of time

Sure.
Maybe you could delegate some tasks to the joomla community? I'm sure, there are people out there that could help you with some parts of the project!
> But what happens if user (like me) use other editor than tinymce
Well, nothing bad at all!
Some of these editor plug-ins are even compatible between different editors!
(BTW - what editor do you use in Joomla!? And why?)
Bye, birdie