Here you have my answers, some agree with yours in certain way.
1.-As you wrote I think TJD is so succesull because of the great effort the koreans did and do to spread it to the world, most of the koreans are very good for doing bussiness, simply the y put on thir minds to put TKD in the minds, hearts and souls of most of the people in this wolrd and they succeded in this.
2.-Answer two is conected to answer number one.
3.-When I was a teen I wanted to learn karate that was the generic name except judo for Martial Arts in my country, so a girlfriend of my high school knew this and took me to her dojang a Koran Karate dojang, the rest is hystory.
4.-Nop, TKD is not the best MA but..... wich one is the best?? all depends in many many things and this is subjetive, what I know it's TKD is an exelent MA that involving good cardio, developing of stamina, good in self defense, a nice sport, etc,etc.
5.-Yes TKD can be a style of life.
6.-What I change of TKD.... tought answer, but I think I would separate the sport side of the Martial Art Side, I would ad more self defense, and I would change the way we sparr I would sparr in some way like the ITF but ading some other resourses like take downs and pins, where only efective techs count, don't like a volley of meaningless kicks, only the good techs will score.
7.-My goals, be a sambonim and have my own dojang, and escalate in the dan ranking, get better inside the martial Art of TKD and my comunity.
Manny