Nick,
Just to sum up what you wrote:
* Toggle keys are ok for things that make sense to toggle. * Prefer alphabetic keys. * Prefer Ctrl-key and Ctrl-other_key for most commonly needed editor functions. If they're adjacent keys, that's sometimes nice. But F3/Shift-F3 is ok too. * Ctrl-key/Shift-Ctrl-key also ok, but slightly harder to activate, so use for less commonly-needed editor features. * [I'm not sure what you think of using Alt keys] * Shift-Ctrl-key is ok for opposite of Ctrl-key. But exceptions to the rule are ok if there's a reason for them. * Shift-Alt-key is ok.
Also, Enrico
* likes Tab/Shift-Tab * suggested using Alt-I for some special indentation behaviour he has in mind. * likes F3/Shift-F3. Doesn't mind the Fkeys so much. * notes that using Alt-key isn't very good given it's used for manipulating GUI elements, and the letters for them can change for different languages. * doesn't seem crazy about the toggle (at least for changing case of a selection), but then mentions that Ctrl-B could still toggle line commenting. * likes Ctrl-Z/Ctrl-Y for Undo/Redo. Likes commonly-used keys to be easy to reach without the Shift key.
I originally posted because I'm concerned about having too many key-combo usage schemes making it more difficult to learn and use them. The phrase I was searching for when I posted was "context shift". You're fingers get used to "Shift-Ctrl-key does the opposite of Ctrl-key", then it's a context shift to go to "Shift-Ctrl-key does some extended behaviour of Ctrl-key", which makes the editor harder to use. IMO, it's the kind of thing you don't usually notice directly, but more of have a feeling that, "this editor feels more clumsy to use than editor X".
It sounds like what you're saying is that you don't see that as much of a concern (maybe it isn't -- it just seems so to me :) ).
Looking at the key bindings for terminal-based editors, I can see how they were limited by not having certain keys available to them (like not always having the named key (PgUp, PgDn, Delete, etc., or not always being able to use Shift with other modifier keys), so maybe they couldn't always be as consistent as they wanted.
I can see it's a pain to move default keys around, since users get used to certain keys. Maybe I'm just chasing foolish consistency too much here. :)
---John