So, I guess the [dev1029]-tag is more about improving the collision detection with the environment, e.g. rocks, so that we won't get stuck on insignificant height differences etc. While this is an important part of collision detection, there is another type which interests me more: collision detection with monsters.

While I understand why you decided to remove the collision detection with other players, removing it for player-monster relationship is imho suboptimal.

Why not leave the collision detection in the game, but only for player vs enemy scenario? Especially if it's done right, i.e. a monster really not being able to pass through a player and vice versa. This would allow us to use more strategies like a tank blocking a monster from reaching the healer at the back.