I could have called this a feedback request, but the author is starting the book a day earlier than it did in New Beginning 1072, so it's not a revised version.
The salt that gave the Blood Flats their color also made them near-impossible to farm. They also flooded with seawater on occasion, and the small collective of which I was a part would need to migrate to the forest. However, the Blood Flats did have their uses; the barrenness of the land provided excellent visibility, the priests had to walk for several days to bring us supplies, and there were a few caves and unpolluted springs. Best of all, some of the rock could be poisonous. Unfortunately, we were having difficulty getting any out of the ground to make into a weapon.
We had rope, of course, woven from the few tough grasses that grew in the less toxic parts of the Blood Flats. It was great for mundane use, but would not stand up long to the Dragon Warlord. Wood had a similar problem. Our only hope of defeating the Dragon warlord lay in stone, and our combined talents.
So, it's an update of The Three Little Pigs, with grass and wood failing to stop the Dragon Warlord, but stone doing the trick.
Sentence 3: if this is a list of three uses of the Blood Flats, make the semicolon a colon, and the commas semicolons. But first make it more obvious how the phrases you're listing belong on a list of uses for the Blood Flats. Good visibility sounds like an advantage rather than a use, presumably because it prevents the Dragon Warlord from approaching without being seen. (Although it might also be a disadvantage, as it allows the warlord to see you. I think if I had a Dragon Warlord as an enemy, I'd want my collective to be in the forest where it's easier to hide rather than in the middle of a barren flatland.) That the priests had to walk several days to bring supplies doesn't sound like a "use" for the Blood Flats. I'm guessing you're saying that it's easier for the priests to get to you through the Blood Flats because of the flat terrain and the unpolluted pools. So sentence 3 might be better as: The Blood Flats did have their advantages: the barrenness of the land provided excellent visibility, preventing a surprise attack; and the gentle terrain and unpolluted pools gave the priests a less demanding route on which to bring in supplies.
I'd move the poison rock into the next paragraph. I'm not sure why we're discussing rope and wood if they're useless. The rock is poisonous, and it would be their best hope of defeating the Dragon Warlord--if they could find a way to extract it from the ground.
I start off thinking the Blood Flats are a barren wasteland, but then they have caves and pools and grass and apparently aren't far from a forest.
Decide whether to capitalize "warlord," and be consistent.