So to recap:
Tide pools work that way because magic, and by magic we mean balance. This is fine.
Other water features are just a 'suggestion', and can be whatever. That's fine too I suppose.
Forests block line of sight through them, but not into them, despite the rulebook making no distinction between LOS crossing a little bit or all the way. Because that's how they solved contradictory graits in Malifaux, supposedly. Shakey about this one, but if you showed up at the store and wanted to play em that way, I'd be ok with it.
It just surprises me that while the rest of the rulebook is really tightly written, the terrain rules have contradictory text and "agree with your opponent" instead of making an attempt at an exhaustive list. Then they dedicate the entire next page to rules that are even more optional than the previous terrain rules, and a large picture of a gentleman with a gatling gun.