The thought that crying doesn’t do anything is misguided. It actually changes a lot internally. Like, sure, it doesn’t change your material circumstances but it absolutely has a proven effect on our mental well-being and ability to regulate emotions.

It helps us to process emotions of grief and tension. It’s catharsis. It has a physiological effect on our sympathetic and parasympathetic nervous system. That exhaustion is the release of tension that, without it, the body isn’t recovering from.

So, on a rational level, yes, crying does actually make people feel better in the long term, even if it doesn’t immediately show signs of effectiveness.

Everyday, all day.

Yet another person who doesn’t understand the basics of logic in that you fundamentally cannot prove a negative. You have to prove the positive. If the positive cannot be proven then it has to be assumed that the negative is true.

Is there proof of successful human cloning? No, thus it is assumed using basic logic that humans have not yet been successfully cloned.

A lot. Genes have a weird ability to activate or deactivate, or simply have a different effect, based on environmental factors.

Look up “Epigenetics”.