These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Some fans speculate that Kenshiro later became the hermit Koryu, the last opponent Ramon (Ryuken) fought in order to become the Hokuto Shinken successor. The fact that there's only two Kasumi brothers and Tesshin isn't shown to be training any other students gives this theory a bit of credence.