Well that was a lot to take in and try and sort through. I would of broken my threads into different threads. I got a bit lost to be honest.
Oyster shell should be offered at all times for hens. It’s a slow release of calcium that’s an excellent part of their diets.
Tums is just a quick “shot” of calcium and Tums should not be a daily additive to their diet. It’s only a bandaid to a possibly bigger problem.
Sounds like your hen laid a lash egg....the blue blob you described. For that there’s basically nothing you can do
Photos would be of great help.
Egg yolk presumption that it was a healthy egg and nothing but a little yolk left suggests a egg eater. Completely different topic that’s behavioral not medical.