Typos! The bane of my existence. Thanks for letting me know. It will be fixed the next time I post an update.
Stone Skin and Favor of The Gods: I have no idea, I never thought of that. I would let the player do it, but then make a point of attacking other parts of their character sheet from time to time. I’ve had a few “OP” fighters in the past. I gave them lots of enemies to slay and would occasionally hit them in their weaker stats.
ZONES: That is just an example of how you can make each zone its own unique challenge. So it’s not happening all the time like a D&D attack of opportunity. It needs to make sense in the fiction. There’s a giant 4-armed serpent-man statue wielding giant scimitars in that zone? Heck yeah you need a STR or DEX save to move in or out of that zone. Are there 3 goblins in a similar zone? Probably don’t need a roll to move past them. 12 goblins? Maybe now we are back to rolling a Save of some sort to move through the zone.
It’s entirely up to you as the GM. Whatever make the game more interesting.