I think the daemon-distance thing could so easily have been slotted into the first episode, showing Lyra and Roger messing about, seeing how far they can get apart.
Then when Mrs Coulter does it differently, we can observe that she's breaking the rules on daemons, rather than have it spelled out to us after the fact by Lyra.
I don't mind that Asriel seems like a hero now - he is to Lyra, and at this stage in the books, whilst not a loving character, a hero is exactly what he appears to be. He's a bold explorer, a rich man stripped of his privilege for saving his daughter, and persecuted by the church for heresy. Lyra sees him as parallel to Iorek.
I'm afraid I'm not a fan of Ruth Wilson as Mrs Coulter. She lacks the glowy, soft, charming angle of her which is what is supposed to captivate everyone she meets. (she does the steely stuff very well - so perhaps she's just lacking direction)