First of all - that RWG pic looks very awesome. I'm happy with the fixes in A17.3 but that just takes it to a whole 'nuther level.
Now, about the whole "food spoilage" thing. There's one mechanic I'd like to suggest, and I don't think it would either impact current performance, or be easy to exploit.
Simply make crops spoil after a certain point. I'm not suggesting spoilage of anything in your inventory. I mean, once a crop has reached a "harvestable" stage, it's not finished growing. The next stage is that the plant dies.
This means you'd have to harvest crops when they were "ripe," and if you missed your window, all you'd be able to harvest is grass (or whatever dead plants give you).
There's already a timer attached to growing plants so this shouldn't be any more of a performance drain than already exists.
One other idea - but this one is for NPCs. Others (including MM) have said that zombies destroying crops might be a thing. If so, I suggest hostile NPCs (bandits or whatever) be able to do the same thing.
Except in their case, they gain health from "destroying" the crops. If it's easy/practical to implement, possibly have NPCs put the crops back to "seed" state instead of utterly destroying them. This gives the impression that they are "stealing" them rather than destroying them.
EDIT: I also had some thoughts about how to implement "permadeath."
The question is, what does "permanent death" mean if you're not starting an entirely new game with a new map? IMHO this means starting over, but living in the same world.
Some things that might help with this mechanic:
- No bedrolls in the game.
- The exposed map resets itself (so everything is hidden and you lose all your saved markers).
- Permanently drop everything on death. OR...
- Drop a backpack with your stuff, but it doesn't show up on the map.
- Lose all your skill points, and/or keep them but have to re-invest them. (The latter is better if you can't reset your gamestage.)
A lot of this is possible via mods, but only if you use SDX, which I personally am against. Ideally all of these things could have a setting in the advanced menu, or at least be moddable via XML.
Obviously these are just suggestions, and to be honest, I'm not going to be upset if the game stays as it is.