I personally would run some enchantments so you can abuse Angus's fog effect. Ramp hella hard then fog every turn. Doesn't do much to some combo decks but a lot of decks require creatures to get in for damage.
How do you feel about Expedition Map? I can see how it would be bad because generally turns 1-3 are artifact ramp spells/Arcum/Arcum food right? Although tutoring for ANY land is nice because you can hit Arcum food like the nexi and Mishra's Factory.
Your missing the best one turn kill with scion. You first swing at someone, stack his ability twice in response to each other. You search for Moltensteel Dragon, pump him with Phyrexian mana to a 10/4. You use the other search ability and pull out Skittles and then proceed to kill someone in one hit.
I run Skyshroud CLaim and its phenomenal. I would highly recommend running it. I know it costs four, but getting your Bayou and Overgrown Tomb at the same time is awesome.
On another note I picked up a Terminus for the deck today.
EDIT: Also how good is Svyelunite Temple?
+ Sensei's Diving Top
EDIT: Why both? We only run one guy worth protecting, and thats Arcum.