About o intervals. 2-3 legs per interval. When do you start looking the map and choose the route for the next interval - right after the interval start or during the rest between intervals?
And about looking the map: you look at the map with high frequency. Do you have some plan or rhythm when to look for this feature, when to look for the next feature, the feature after the next, when to look for the next leg? For instance if the leg has 5 features how many times you will look the map - for features, attack point, in - out, next leg route choice...?
I never anticipate the coming interval during the rest. About map reading frequency, it really depends of the type of terrain, and visibility. Seldom, you can see all the features from distance, sometimes you need to follow a curve or run with compass for a while. The key is to always adapt to the situation.
Ever worried to twist your ankles? Especially downhill intervals seems risky close to highvalue events. If not problem, how do you prevent this?
Never twisted my ankles seriously, so they are still in decent shape (no need to tape them as well). In my "before Breakfast routine", I use about 6 minutes in my BOSU ball to strengthen them.