1. If you killed some monster and forgot to take its "content" do not cry.
10 days after it will be there. Maybe 100 days after.
No problem.
2. I had many problems with caves lighting with The Witcher 3.
Not at all with Risen.
But if you want more light, please - torches are available.
lvl16
Now i am with Inquisition
Why?
Well, i like cast magic fireballs but this is able with Inquisition only.