Woman Time Lords can control the way they will look when they regenerate, while male Time Lords cannot. This was established in Classic Who, when Romana regenerated.
Also, the Doctor wanting to be Ginger is not about the hair color. In Gallifrey, the only ones to have red hair were the people called Heroes which were beings who were time-sentient (meaning they could see all of the time at the same time). So I doubt they will ever make him ginger.
NO BUT WHY DOES HE REACT LIKE HE SUDDENLY RECOGNIZES THE NAME
I JUS t
profound bond, that’s why.
I bet he’s been hearing that name in his dreams, and just for small moments in his head ever since he got back from Hell. Little whispers in a language he couldn’t understand but for some reason he registered as saying “Castiel.” He remembers the walk from his gravesite to the abandoned convenience store and how lonely he felt until that screeching started, and as startling as it was, it honestly filled him with an irrational sense of safety, if only for a moment.
He remembers Hell, and while he may not remember being pulled up from perdition, he remembers a scorching hand grabbing his shoulder and Enochian whispers of “I’m Castiel, I got you.”
I’ll just go and cry now.
Castiel was also mentioned in a summoning ritual that the boys used in 3x06. Sam was the one who recited it, but I wouldn’t be surprised if Dean was familiar with it too. Although, since it was recited amongst a bunch of other angels’ names and they still didn’t know who/what Castel was until they met, I suppose they just didn’t remember. Sam did read it out of a book.
I think that a lot of the reason Jarvis has become so human is because Tony treats him like he’s human. Tony talks to Jarvis in a very colloquial way. He says “you up?” when he knows damn well that Jarvis is operational. He says “throw a little hot-rod red in there” instead of “paint components x, y, and z with red paint #20.” Tony treats all his machinery like that—Dummy and You, especially—and Jarvis is no exception.
Jarvis has become much more human since Iron Man 1. He actually displayed emotions in Iron Man 3—specifically when he feared for Tony’s life, his voice sounded terribly frightened, and in instances like the second gif where he said “I need to sleep” and not “My battery is depleted.” Jarvis has grown and changed, as any self-aware creature does. He has become human because he is treated as such.