If you set max events/landmarks to 0, it is still possible (and quite common) to get 1 event or landmark. See eg game 5985620.
It is easy to reproduce.
If you set max events/landmarks to 1, and min to 0, it may be the case that you always get 1 rather than 0. I cannot be certain, but I tried it about 20 times and always got a event or landmark.
You are right, the MAX_LANDSCAPE=0 case is easy to verify with a few tries.
In the MAX_LANDSCAPE=1 scenario, I had 1 case in about 30 tries with no Event/Landmark, which also seems off, considering that roughly 15% of games should have no Even/Landmark.