Obelisks are just extra experience and skeletons. And they are simply interesting blocks. I don't believe in their mythical value; the difference in respawn points based on the value of the contents can be so huge that obelisks are insignificant compared to that.
Water artifacts are also a plus; they reduce the imbalance of utopias, when one player gets 2 artifacts, and another gets 5. Besides, utopias are often chosen for the money, not for the artifacts, and they always give money for them.
I don't quite understand why you want to change the SOD (Shades of Darkness) when there is VT (Void Tears) for SOD, where all this stuff like 3 stacks, 2 levels, the absence of obelisks and cartographers, etc., has been implemented. Play it and enjoy.