Sea troll kings and troll kings are fine. They are expensive, and require upkeep, so they do not yield the kind of growth curve that fetishes/stones/clams do.
Blood stones may be the most expensive free gem producer out there but its still cheap. I have mass produced them without too much trouble as Abysia. Granted they are not as good as clams and fetishes...
As for being an important +E boost, you should be able to do fine with earth boots and staff of elemental mastery... how many +E items do you need??
Also eliminating fetishes/stones/clams makes the forge a little less of a game winning global. Still very good! But not grotesquely awesome