Looking at your mana curve and the cards in the deck, are you content with giving your opponents T1 and T2 to act? All your one-drops are non-creature spells, and you only have four two drop creatures (I'm not counting
Boneyard Wurm, because you can't play it until you have creatures in your graveyard).
What about some one-drop mana producers, like
Avacyn's Pilgrim, or a mana recycler like
Arbor Elf. Use them for mana early, and then use them as chump blockers to fill your graveyard.
That said, you're only playing one
Boneyard Wurm. I prefer to see more multiples in decks because it increases the odds I'll get the cards I want/need for a win condition.
Serra Avatar looks good on the surface, but I normally recommend against it unless you are running a lot of lifelink. With a couple of
Thragtuskand some
Nearheath Pilgrim, you'll have some lifelink, but not the amount I'd want to see if running
Serra Avatar. You're not going to want to block with your Pilgrims if you're going to rely on their Soulbond ability to make
Boneyard Wurm bigger. Why not add some one-drop lifelink creatures, like
Trained Caracal. That way, you can get an early start on Lifelink (especially with a
Rancored Caracal), and will also have cheap chump blockers to start filling that graveyard.
So, I believe there is potential here, but I believe you need to refine what you have to make the deck a consistant performer.