What I want to think further about is whether it makes sense to elevate the "is it in my control?" to a first level division
True, and very good point. If one is powerless but enjoys thinking about something – maybe the outcome of match of one's favourite sports team – then there would be nothing wrong with that. For me – by chance – it happens to be that everything I do in fact think about but cannot change are things which make me very unhappy (primarily contemporary politics).
So, more correctly, the first question should be: "Does it cause pleasure?"
If it does bring pleasure, it should be analysed further (left half of chart).
If it does not bring pleasure, it should be avoided unless it is a feeling, in which case it should be allowed without getting lost in it (“feel through it but avoid melancholy, etc”, because suppressing feelings only causes problems down the road). This basically awards and exemption to unpleasant, but natural & necessary emotions (e.g. grief, loss). Technically, with sufficient foresight, they could be handled by the left-hand side of the chart -- but it might be valuable to grant them a special category like this, because they're usually overwhelming and have a tendency to shut down rational thought. For example, if I were given the option, I (or certainly a younger me) would probably decide that my grief is limitless (unnatural) anyway and thus to be avoided (equal parts naive to or wilfully ignorant of the fact that this will cause psychological baggage for the rest of my life), rather than allow myself to feel it, to work through the emotion (and thus trade unpleasantness now for more of a spring in my step later).
Thank you, Cassius!
I feel a lot better about this revision!
Revised version: