Further question: Do I play this with flat fingers or curved fingers?
1) This piece demands homogeneity, fluent way of playing, relax. May be it can only be achieved by a unified style.
2) If I acquire a fluid, homogeneus style, other pieces should be easier to learn, because the general aproach to the keyboard is already learned - that is , I would not need specific solutions, I would just play mostly all the time at the "usual" style position (flat or curved)-.
(Please suppose some common sense in my actual teacher).
control yourself with your ears, not your eyes.
i wish it was so easy... you always need specific solutions! i've recently had a somewhat similar discution with another piano teacher who said "the correct wrist position is..." - there is no "correct" wrist position, or finger position, or body position! it all varies from pianist to pianist, and especially from work to work.
I think I've figured out why I should use 131 243 instead of 132 132. Because the latter requires you to play with your thumb under your palm which, according to Chang's book, is a no-no for playing fast.