There is no way we will rewrite a book or put a whole course synopsis here, but best practices for safe food handling can be summarized with
labels on food
Depends what's reheating.
you can
Unless the meat was prepared in some sort of sauce or gravy, reheating usually makes it too dry to enjoy.
yes
To at least 165ºF
Only after repeated reheating and cooling.
Ask hitler?
most likely because the water is reheating and starting to boil. most likely because the water is reheating and starting to boil.
Because they cant be bothered
surface to core temperature islow
yes you can but do not put a cover on it while you are reheating it