Got the 5-0 with the above list featuring Life From the Loam.
I've played Loam in six leagues, going 23-7 across two different lists. Four of those leagues were with the verbatim list posted above (17-3) and two were with a modified version that cut the Salvages/Ichorid for more Portals/Loams/Leyline of Sanctity (6-4).
Obviously a small sample size, but I think Dakmor Salvage may too important to cut. In the two leagues and a bunch of practice matches without it, I've had trouble reliably triggering the Bloodghasts or ensuring a land drop to get Loam going. Dredging a Salvage often accomplishes both in a single turn.
I can't overemphasize how good Life from the Loam has been. What's really impressed me is how good it's been against Shops and Eldrazi, which were the two match-ups that have given me the most trouble. Loam doesn't just help keep Marit Lage looming, but also undermines the ability of Shops and Eldrazi to overwhelm the board with threats by recurring Wasteland. Null Rod and Wasteland consequently buys a lot of time. The Spheres, which I keep in against Eldrazi, have also become more effective at keeping Thought-Knots and Smashers off the table with a stream of Wastelands flowing.
Thanks for the run-down on your sideboarding, I find your approach very interesting. I've always kept in the Shops and lockpieces against the Oath/Survival/U-Wasteland decks to hamper the ability to find and play answers to Marit Lage or the dredge plan and prevent their threats (e.g., keep Oath off the table or Survival from going off in a single turn through a Sphere).
But it looks like you are going for a more all-in attack strategy by keeping the threats and tossing the prison element. I'm going to try that. I think that might be the better approach (especially on the draw).
Also, what are your thoughts on Spyglass vs Needle? Are you going for the latter because you tend to board out Shops?