No, there's no built-in support for customizing TinyMCE in that manor.
Regarding restricting image insertions I guess you could remove access from global folders in the file management and sort of achieve something along those lines.
Thanks, that was what I thought, but thought I'd check in case I missed something obvious.
You could also hook up a save event and filter the XHTML properties' markup depending on role. For example replace all H1 elements with H2 or strip IMG elements.
Are you able to display different Tiny MCE editor options to different users depending on their role?
i.e. remove the option to add images for certain users, or removing certain formatting options, e.g. "Heading 1" for a user?