Jason, I think you've done a great job of pulling a load of colour-related ideas together. Thankyou.
One area where I struggle when colour correcting - e.g. using a colour balancing effect - is knowing what colour to add/emphasize to the current colour to achieve my desired colour. If I were mixing paint I could use one of the readily available colour wheels (cardboard rotating things which show you what you get if you add one colour to another). But I don't think this works for an RGB screen. Do you have any ideas on this - ever seen some kind of app which might help reduce the amount of trial and error I have to go through?