I notice the intentional meanings the writers put into the show that may go over other people's heads, like Luna's depression in 'Do Princesses Dream of Magic Sheep?', but I wouldn't consider that being critical. Most analysts in the fandom are just really creative at coming up with headcanons, in my honest opinion. Pinkie Pie isn't afflicted with Dissociation Identity Disorder or Bipolar Depression and Twilight isn't Obsessive-Compulsive. The adult fans of the show try way too hard to make the show seem more mature than it really is.
Mmm, I guess so. It's a habit of mine to not look at things at face value. I always wonder what's going on in a person's head that they're not letting out and I often gravitate towards characters that have a lot of deep thoughts over characters that are simple and easy to understand. Does that make me critical?
It depends. If I'm just looking to be entertained, I'm easily amused. If I'm writing fan-fiction based on its material, well... I like things to make sense. Whenever I have to do the show's work for them, I do not enjoy it. And MLP: FiM is rife with nonsense.
I can be critical. I have even been called overly-critical at points, but only on things that really intrigue me. If it doesn't intrigue me, I'm not going to waste time analyzing it.