What I think is an auto-include in any Commander deck, whichs Commander can gain +1/+1 counters, is cauldron of souls.
Also, if I see it right, you play maybe 4 cards that draw you cards. Which, according to my experiences, would leave you empty handed quite quickly, hoping to topdeck something useful. I'd up that to 10 to 12 card drawers.
The card advantage situation isn't quite as bad as it seems, as you can always Green Sun's Zenith, Chord of Calling, or Tooth and Nail for Regal Force, which almost always draws at least six cards. I certainly wouldn't mind having more card advantage, but I haven't found many things worth adding.