Thanks for the advice. I'll probably go with Cairne for the silence/poly magnet
A couple of questions
1) Why Alexstraza? Paladin's do have a couple of ways to heal up, and there are more painful 9 drops (e.g. Onyxia)
2) I do have the beast, but I always considered it garbage outside out a hunter deck (even then). It tends to be taken out quickly at 7 health and I just gave my opponent a 3/3.
Paladin has trouble closing out a game, Alexstraza is a 15 damage nuke on their face, an 8/8 body, and 15 damage fits just nicely into Ashbringers overall damage potential. She's more consistent than Ysera and her Battlecry is way the !@#$ stronger than Onyxia's easy-to-deal-with Whelps. And in a pinch, she offers (on average) a 7 health heal up to a 14 health heal which can swing the game around if they can't deal with Alex.
RE: The Beast
You want him removed in a way that burns their removal for huge threats like Ragnaros, Alexstraza, Grommash Hellscream. Cairne or Sylvanas usually just draw silence since a lot of popular decks have 2 sources of silence, which is good if you are Paladin because it hard-counters Tirion, while most other classes don't really care about their %^-* being silenced. A 3/3 is pretty easy to deal with, he's a high-risk play if you have no board presence or the enemy board is swamped with minions, but if you can play him on an empty board, he usually requires at least 6 mana worth of response excluding BGH/Poly/Hex, BGH is the worst, but it's the one I play around the most.
He's also good in super-lategame when there are no answers left and you're holding say, a final board clear for 4 mana like Hellfire, and you top deck The Beast. He's a really meta-based card, if Druids and Handlock are fading out, he's worse, if they are everywhere, he's better.