Thanks to @diegomarino80gongo for his suggestions (and to @zfoxfire for the summary of what is presumably going on under the hood).
I wholeheartedly agree with practically all Diego's suggestions, we seem to be on the same plan here! A few, marginal, comments:
Animals: "too many edibles animals": well, a lots of animals ARE edible!
"i'd like to see some disease on cattle": nice idea! With two caveats: 1) It should not be (or only very very marginally) random, but usually with some reason: not enough food, or water, not enough care and so on. Otherwise it would become a lottery. 2) Healing herbs are a nice touch, but finding herbs in the tall grass is again mostly a lottery.
"more dangerous animals": well, not all Earth areas are (equally) filled with dangerous animals -- which played some role in civilisation evolution --. But mostly, it should be a matter of reasons and equilibrium: dangerous animals should come with techniques and tactics one can learn, become adept at (perhaps gradually) and adopt to decrease the risks, as most rural populations do in absence of powerful, mechanical defence and attack tools. Otherwise: again the feeling of playing a lottery game.
Threats: "fire, earthquake, flood": ok, we have no control on earthquakes, but we can learn where they are more probable. Fire and flood: for the major part, they are caused by humans themselves, the exceptions being usually periodic, but then we enter the field of climate models which is rather complex and daunting and I do not expect to even be implemented in a game like RW.
"[human] diseases": same as above: there should be reasons (thanks for listing the most important) and ways to react.
Anyway, you depict an environment much like the one I would imagine myself. Thanks for such a summary!