The first revision to No Eden was the easiest and was suggested from multiple sources, first at Reddit and next here: replace Serra's Blessing with Brave the Sands. That change is so obvious it would've bit me if it had been a snake.
Goldfishing the deck, the benefits of this exchange were obvious: Voice of All becomes nearly impossible to get around. Suntail Hawk drawn in the mid or late game has value. Oathsworn Giant becomes a Very Big Deal.
The other choice to make is far more problematic. Doing some basic Gatherer research for cards for this deck I came across Gideon Jura-I was looking for more ways to destroy tapped creatures. Planeswalkers always have a massive impact on games so it seems like it would be a shoe-in decision.
Well, Devouring Light has some advantages, too. Cheaper, especially with Convoke in the mix and I already own copies of it so the My Money rule kicks in. The instant speed aspect is important and the other two abilities on Gideon aren't terrible but they aren't great, either.
The only thing to do is test them out. Fortunately, Cockatrice offers me an easy way to swap cards out, so that's my next stop!