There’s a UI element I haven’t brought up yet. I’m sure you’ve seen versions of it elsewhere, I’m not sure what it’s called though, so I’ll just call it Fizz for now, because that’s terse. It appears centered just above the selection.
Unlike MS Office’s Mini toolbar, Fizz always appears above the selection and so never obstructs any part of it. It also packs less buttons by default (copy, cut, and styles, plus some other common commands), since it really is meant just for quick edits.
Fizz is basically just an abridged contextual toolbar, and the user can always get the full toolbar by clicking on the “…” symbol. And, yes, Fizz is customizable.
Fizz, along with the contextual toolbar, also provides a way to get to the features of Direct manipulation snippets, like spelling suggestions, hyperlink editing, etc.