I think Carson's support of Alfred might just be because Carson likes Alfred, whereas he was indifferent to Gwen. With it being so difficult to find another footman (remember they had difficulty finding one until they got to Jimmy), you would think that they would discourage this. Feels a little off to me. Also, doesn't Alfred only have a half day free, how could he just be able to hop a train to London for his test last minute? Didn't Carson object to Ivy going to York for the theatre? Not like the Ritz test is some sort of job training thing since he's not going to it to replace Mrs. Patmore.
Yeah, was not happy that Thomas asked Baxter to invoke Sybil's name like that.
Maybe you have a point re: Bates being the only person who could touch her.