People are taller just because of the way our world is coming. The taller people tend to play sports, and there seems to be a lot of people playing sports.
yes,shorter people do have more energy then taller people.
yes
Taller people need longer arms so they can tie their shoes.
the author of do taller people run faster then shorter people is Jim Liffer
yes it is possible for people to grow taller than 8 feet.
This is a good question and observation. People who live in Europe or europeans' descendants or people who live in Northern Asia usually seem taller and larger than people who live equators or in hot climates (except Africans). However, I wouldn't say people are usually taller in colder climate. I would say they have high body mass. According to Bergmann's rule, when the air temperature is consistently high, people usually have low body mass. Similarly, when the temperature is low, they have high mass. However, there are exceptions.
no
You grow by your age
Yes
Yes
It depends upon genetics. Some people will grow again taller and some will stop growing.