"there was alot of empathy there."
I think that everyone was in a nearly panic state. There were too many of them and it was all you could do to watch your own ass let alone watch someone elses.

"...out of nowhere here come Arya Stark."
Yeah, honestly, that was lazy writing. I would rather have seen her slowly working her way towards him. The suspense of wether or not she would make it. The last time we see her before that, it doesn't seem as though she was anywhere near there. But, what the hell.

"The Hound---I have a feeling that really was keeping him from fighting back was that there was so much fire involved."
I thought that was exactly the reason. He certainly wasn't somone to avoid a fight.

"What about the dragon that was overrun by zombies? I wasn't clear on that"
Wasn't he the one that joins her when the batle is over. He lands next to her and protectively wraps a wing around her. Or was that the wounded one that Jon was on? I thought Jon's dragon crash landed and died. Maybe I'm not clear on that, either.

"he and the Night King are somehow one and the same,"
There is a possiblity that this is the case. That he wanted to kill Brann so that he would never become the Knight King. There are a lot of hints to that effect during previous episodes. In one episode, they show the man who became the Knight King with his arms stretched out in a Christ on the Cross type of pose. Brann sees this, and when he goes back into his own body, the camera pans out and he is in the same pose.

I didn't think the battle would end there. There are still a couple of more episodes. Will they attack Cierci for betraying them? Do they even have a large enough army left to fight with? We shall see!