... but her cutie mark is about singing or music or creativity, not magic.

A valid point. What I meant was, starting to be able to use her magic is a sign of growing up - and gaining her cutie mark is another sign. Since growing-up is happening, I therefore conclude that she is proceeding steadily cutie-markwards.

As long as the CMC cutie marks remain unattained, I'll be convinced that The Show Stoppers already introduced us to what they are about

Yes, me too. I think Sweetie Belle's is about singing (which is also why she has such a wide vocabulary;all the better for impromptu lyrics-writing. I think The Show Stoppers made it clear that even before a cutie mark is visible, it has some effect on the pony...)

I agree it's not very direct. However, the way it looks like to me, is that Pinkie Keen is about the virtue of belief over reason, and Leap of Faith is about the potential, indirect harm of belief over reason.

I can see how you get that conclusion about Leap of Faith, but I'm still not seeing the connection in Feeling Pinkie Keen.

The entire concept of Feeling Pinkie Keen was that Twilight had a belief (Pinkie Sense can't work like that!) which was not reflected by reality (Pinkie Sense continually did work like that) and which caused her significant stress until she managed to let go of it.

So, it could be said to be about the virtue of (experimentally verified) truth over belief...

The subject itself is also something I don't much want to get into, as discussions on this subject, even in nice places, get pretty volatile and have a way of getting people hurt.

...okie dokie lokie. If you think we're getting too much into the danger zone, just say so and we'll drop it. (I think we're safe as long as we stick to what the episodes were about and steer away from whether either is a good or bad thing).