I made a deck that was similar to this deck when I first saw
guttersnipe 
, I put some
blood artist 
and
deathrite shaman 
s in it and based was around casting cheap burn spells to kill all of the enemy creatures and kill them slowly through passive abilities... this type of deck is going to be substantially weak to control based decks, as they do not have creatures for you to kill, in that regard I would try to put in a lot of burn you can throw at their face on your sideboard for when you run into decks like that.
deathrite shaman would be a great addition to this deck because he can take sorceries and instants in both graveyards and use them against the enemy; if you put him in I would also consider throwing in sources of green mana because then you can use his 3rd ability to take out creature with undying, reanimator targets, or just surviving the early game against a agro deck.
I would suggest adding draw spells like
sign in blood 
,
faithless looting 
and
wild guess 
, if you run out of steam in this type of deck your going to lose very very fast , you need to maintain a constant stream of cards; not to mention they are sorceries so they trigger
guttersnipe . I would also consider adding
underworld connections 
,
bloodgift demon 
or
staff of nin 
they all have different uses,
underworld connections s will help you keep your momentium constantly but take up one of your lands for its use, Note: always put it on a basic land, that way if they destroy it you are not out a dual land.
bloodgift demon is useful because hes a 5/4 body on a
underworld connections type effect, he is slightly less reliable than the other 2 options because he is susceptible to creature removal;
staff of nin is easily the best choice because the draw effect does not hurt you and it offers the ability to remove really small creatures and ping your enemy for 1 damage every turn, the only downside is that it costs 6 mana.
some more kill spells and sweepers to consider are
victim of night 
,
tribute to hunger 
,
tragic slip 
,
rolling temblor 
,
mutilate 
and
blasphemous act 
; I find that
victim of night is more of a sideboard option but that it is becoming more relivant as the zombie and vampire tribes become less relivant. Personally I would consider discarding the
pillar of flame 
s from the deck and replacing them with
rolling temblor , temblor takes out the majority of zombies you would ever run into and you can flash it back from the graveyard, just seems easier to kill them all at once rather than take them out one at a time.
I would get rid of the
disentomb 
s, they arn't going to be that useful most likely, I would replace them with the
mizzium mortars 
and
devil's play 
that p0p31n3ss suggested; both of those spells are going to be very important for a deck like this, mizzium mortars can kill any early threat and provide a late game wipe if you need it and
devil's play offers dirrect burn to use against the enemy or the ability to kill something really powerful, for a deck like this I would consider running 4 of each.
I would suggest geting 4
dragonskull summit 
s and 4
blood crypt 
s if you are able, they can offer mana fixing that is very important at some points in the game. I would also consider adding 1
stensia bloodhall 
to the deck, it allows you to hit your enemy when you have a prolonged game and you are running low on cards, its not ideal but it can be useful, plus the damage it deals can be redirected at planeswalkers.
I could say more but it feels like Ive said a lot already, sorry for the big wall of text. Note: I would check out some of the threads around the deck help section, the one that Niche made on BR control could offer some ideas on how to improve your deck.
