Tormented Hero is amazing because he's two-power for one mana and his triggers provide a bit of reach while putting counters on the Pridemates. With Nimbus Wings he's a 3/3 flier, which is pretty huge in this meta, especially on the second turn. I like him a lot.
As far as Guul Draz, I don't want a 1/1 for one in my deck so I don't want this guy. I thought about adding Ordeal of Heliod into the mix and treating him like a Trained Caracal, but this deck has a problem casting its white two-drops the turn after a black one-drop (there are only six basic plains). In Boros, Caracal has seven Auras plus the three Paladins as viable T2 plays that let him swing as a 2/2 lifelink. Here, I can't do anything like that because of the mana. Unstable mana makes for a slow and clunky aggro deck.
As far as Kalastria Highborn, yes I feel she's worth it. Most of this deck's creatures are just Bears but all of them have upside. Even one Shock is a substantial amount of reach for a deck as aggressive as this and she's never dead because she triggers her own ability. The ability also has synergy with Ajani's Pridemate and helps race other aggro decks.
I thought about adding Mentor but I don't have anything like Goblin Rabblemaster to really abuse him and with only 21 lands in the initial version, I was afraid I'd never have the spare mana to sink into him. I went to 22 lands so I could add another white source to support Brimaz, but I think I'm going to cut him and go back to 21 after having just played five test games or so. The
cost was too rough and I got up to five mana or more too often for my liking. I think I'm going to add Graveborn Muse as my draw engine in those two slots because it doesn't require any mana investment to sustain and also because I have a bit of life gain to offset the loss.
I've updated the planner, above.