I finally found a working HTMLControl to show and Edit HTML Content for Windows Forms Applications.
It uses internally a webeditor Control, and works great.
I did not verify memory usage :-)
Maybe this link will work!
I have modified it to work with tinyMce.
Normally it is in NON Enabled Mode.
If it goes into Editmode (DesignModeEnabled=true) then it shows the tinymce
If someone is interested in my code let me know...
i have made some screenshots.
And here i explain how you can communicate with the hosted webeditor, resp. tinymce
SOURCE CODE HERE