Quote: Hard to say without seeing them... Solid opaque could be a chick or a rapidly rotting egg. More likely to be a chick though. The black blob could also be a chick. I use an LED torch at night and check all the eggs in one go, it helps to have comparisons on hand. Best wishes with it. If you do have one of the random eggs that rots very quickly, you can smell it through the eggshell pretty fast. Also if it's gone bad it won't hold heat like a normal egg, it loses it very quickly and takes a longer time to warm up.
Quote: I make allowances for clumsiness, but not deliberate killing.
Some of my best hens have made a mistake with one chick or another. But with an intentional killer hen, there's no mercy from me.
Each to their own and best wishes to all. There is always the exception to the rule, but unfortunately it's often too costly in time, effort, finances, etc to 'work the kinks out' of a bent-brained hen or rooster. Or anything else.