WIKI Needs lots of attention
Allow the WIKI tab to allow for Rich text editing and formatting with embedding of Images.
Export and import document formats like word.
Make the tree control to remember your setting to be persistent in your last selection.
Using something like a Word OLE type of control could make this an easy win.
Phil Spokas commented
Definitely needs lots of attention, but, if it's to be a wiki, make it an actual wiki as generally understood.
OLE and rich text can stay in OneNote IMO
thas is why I have to give up wiki and choose onenote