Bug corpses abuse
Clearing bug cave will leave multiple bug corpses which can be easily used to increase players speed
So any player strong enough to clear bug cave will have multiple bug corpses that can use to seriously increase own speed and dexterity. While corpses decrease willpower, once the player have 1 Willpower, there is no other negative outcome to the player for eating the corpses. Willpower can be easily trained back using morgia roots therefore even Willpower decrease is only temporary.
Possible solutions:
1. Once Willpower is at 1 - corpses no longer give speed and dexterity bonuses.
2. Once willpower is at 1 - potentials start to drop for willpower. This is more painful than Willpower drop itself.
3. Once willpower is at 1 - other stats start to deteriorate.
The final solution can also be a kind of a mix of the 3 proposed ones. So i.e. at first potentials start to deteriorate and once potential is at 1 other stats are next in line... etc.