Egann,
Alms beast is there to deal with Aggro decks, due to them producing mass amounts of 1/1, 2/2, 3/3 etc. I'd get rid of one of their creature, and they gain life, basically a pseudo Devour Flesh. It also picks up Desecration Demon's slack when against aggro decks since they have infinite sacrifices. I keep both Alms and Demon in Game 1 and vary them both based on the type of deck i'm playing. As for Blood Baron, He isn't necessarily in this deck for his +6/+6 flying ability, he is in here for the fact that he is pro W/B and has lifelink along with it. As elpablo said, I don't really think Diabolic Tutor is a good card for this deck, I would have to replace it with the cards I'd want to get, so I can search for the card I want.
elpablo,
Erebos Is a good option, but I don't really know if it is worth it or not. A 4 mana enchantment creature at 5/7 with a sign in blood, negates opponent's life gain, and indestructible isn't bad, but I'd prefer underworld connections than his draw ability. Plus, I rarely get to a stage where I have 5+ Black devotion, and simply put, i'd prefer to keep the slots open for Blood Baron's, Obzedat's, and etc, rather than for Erebos. Maybe if a brand new "Super Life Gain" Deck comes out that completely dominates, I can consider him for SB but other than that, he is pretty useless in my opinion.
Thanks for the advice guys, I really hope I can help make this deck top notch by the next FNM with your guy's help.