Actually, there is one thing that could be changed (and probably should, in my opinion) that would fix that.  After looking through it again, I noticed that the formula for swallowing and thus also struggling had changed from using a character's BAB to using their level.  This is another buff to casters that I hadn't even realized was there, and switching it back will go a long way toward shifting the perceived balance away from casters, as this way more martial classes will have a significantly higher base bonus (+5 most times at level 10), but casters will have spells and whatnot to even it out.<br/><br/>Also, I've mostly finalized my character (although I do have a secondary one ready, in case this doesn't work) as a druid with the Cave Druid archetype and the goo form trait, with her background being a sentient ooze who now acts as a guide for those going into and out of the Underdark.  Seeing as how the Underdark is more prevalent in this setting (and we have at least a few characters likely originating there) I figured this would fit in a little better as well as still having it's own definite niche in the party.