I've played around with this and you can quite easily make the game give chance of event occurrence or other such things
- player has a 3% chance of meeting slime enemies
On the world editor first page bottom box I added this to reduce enemy spawn rates so I could scavenge more
And you can add additional parameters where needed for your desired fields, I've also added quite a few new enemy types on my stand alone instance I've spent more time toying with its configuration than playing xD and still enjoy it because I'm learning as I go
I do like your command prompt design for the success and fail chance