Slow motion camera's, like the ones used in Cricket, are stupidly expensive and have a very small field of view. You'll notice they only every have them trained on one area at a time (usually the bats man) and will have 2 of them at most at the games.

To do something like that at Rugby would require 100's of them and the director would need to keep changing between them everytime a ball was passed.

Hawkeye is the same thing. Couldn't implement it over a whole rugby pitch with an acceptable accuracy, or even with conversions.

Can it also tell the mood and feelings of the ball carrier?

I liked the camera they used about 10 years ago that followed play down the touchline on a track.

Didn't that get removed because someone crashed into it and got injured?