Why is Edmure Tully's hair long but his beard is short?
I think Margery Tyrell's capitulation is totally calculated, she has an in-born talent to come out of any situation on top and smelling like a rose. But, I think her motive is about Loras and the fact that he is losing it. I think she thinks if she appears to be converted, it will lead to his release.
I like to think that Sam's decision to take the sword was 70% "This will be super-useful" and 30% "Fuck you, Dad."
DebetEsse - I agree with that.
Well, Sam knows it can kill a White Walker, so yeah, useful. but definitely piss off father.
I think a healthy dose of "I need this more than he does, and know better what it's good for" which pairs very nicely with "and fuck him anyway".