I'd drop the miscalculation for creature removal/ bounce (StP or Aether burst) and try the Brood Sliver for pete's sake! Yes, at five mana it isn't very fast, but the ability (especially with the Shifting Sliver) is great.
I'd play Quick Sliver instead of the metalic sliver. This way, all artifact removal become dead cards and you can keep mana open for you counterspells.
*bonus: my own sliver deck*
2x Mistform Sliver (vs Zombie decks
)
3x Shifting Sliver
3x Synapse Sliver
4x Winged Sliver
2x Brood Sliver
2x Horned Sliver
4x Muscle Sliver
4x Quick Sliver
3x Cryptic Gateway
2x Weird Harvest
3x Forbid
4x Naturalize
4x Tropical Island
10x Forest
10x Island