Regarding your last point. I've noticed the same thing, but it makes it even more satisfying when you manage to pull it off. For instance, I had a Frost Staff run where I was consistently able to kill exploding cubes with the cold projectile, causing any adjacent enemies to be rooted and get hit by the death blast.
You did mention player abilities so I'm sure this isn't anything new to you. But when it was new to me, it felt really good having discovered it!