>>2280527She seems to be just as good as the others to me - on a technical level at least, I'm no art critic. Of course Miya-chans unique style and talent overshadows her a little, but it's not like she's unskilled. Just a bit too humble, and she lets her nervousness gets to her sometimes is all. The show just likes to focus on her bad moments I guess, since they often make for a better story.
But as you said, if she finds it in herself to give her absolute best, then she can accomplish some really great things.
As for her personality, well, that's just how she is - of course that will change as she matures. But I just have to say, that was one of the main reasons I fell for her so hard, so I can't be objective there.