Intuitively speaking broken arm and broken toe are comparable. Broken arm is worse, broken toe is still bad. I’d rather get a broken arm than torture for 50 years, or even torture for 1 day.
For sliding scale of severities: there’s a very difficult to compute but intuitively satisfying emphasis that can be imposed so the scale can’t slide. It’s the idea of “bouncing back”. If you can’t bounce back from an action that imparts negative utility, it forms a distinct class of utilities. Compare broken arm with torn-off toe. Compare both of those to 50 years of torture.
P.S: If you’re familiar with Taleb’s idea of “antifragility”, that’s the notion I’m basing these on.
First survey and comment, and I liked it too! (Including the bonuses, especially the reward question :)