WYSIWYG
A WYSIWYG editor for posts and comments
Lol this could mean 100 different things. Do you have an example of what you mean?
This is already sort of a WYSIWYG editor
Those buttons will still exsit but you can switch from markdown mode to a WYSIWYG mode. In markdown mode you will see the markdown syntax but in WYSIWYG all markdown syntax is hidden but the text field renders it in markdown.
I believe that's what the preview icon in the top right does?