Both very good questions. The only person I could think of who might be defeated by a cat would be some kind of spren, like Syl or Pattern or Wyndle (because they would either be fascinated or confused or just too kind to fight an animal, though that's assuming they'd never seen one.) But I thought about that for an impressive three seconds so I'm not totally sure lool. What about you?
As for Shallan, it's complicated? I didn't like her in the first book, I loved her in the second, and I was torn in Oathbringer. She's completely brilliant, creative minds are wonderful, and I live for her quips, and girl power is great; but she can be whiny and unproductive and... yep, annoying at times. She is growing on me though. I hope that's not too ghastly an opinion haha.