Yeah, I can see how you can use trees and such for a defence that's far better than walls, but nobody can seriously think that's the intended behaviour. It's unintuitive, unrealistic and just plain ugly. Incorporating buildings into defence is reasonable, but in my proposed system it would be suboptimal because they cast too big of a shadow. Same goes for multi-layer walls (ugliest thing about Salem IMO). And I don't think you fully appreciate just how big of a nerf limiting braziers by LoS is. And it raises the player skill factor a great deal when it comes to both base design and base assault, it's so obvious that I can't really understand how anyone could disagree.
Anyway, the point is to make levelling a base a lot harder, but at the same time the stealth approach makes stealing a lot easier. There should be profit in robbing other people, but not in destroying them completely. If you slaughter the sheep instead of shearing them you'll soon run out of sheep, and then wolves will leave the game when their food supply is gone. So yeah, the only profit in destroying bases should be indirect, ie removal of people who have a negative effect on your bottomline.