I am facinated by Muay thai, and I will be sure to investigate it since you say it is the most effective striking system. Yes, I would much prefer to finish an opponent on my feet too, - if I have the strength, speed and skill to do it. It is dirty down there on the ground and I don't want to roll around in the dirt or hard floor.
I am also facinated by the few videos I have seen where a skilled BJJ fighter can confidently defeat a skilled karate figher, or a huge wrestler or kick boxer.
So it seems that an 8 year old can steadily learn some BJJ skills and in a few years, have enought skills to defeat a school bully whose only advantage is his bully size and bully strength. Of course, my 8 year old is learning some striking and blocking skills too.
Yes, it is as you say, it is better to stay away from trouble and fighting. The blackbelt at the dojo says "It is easier to stay away from trouble than to get out of trouble." So we are not going to be walking down any allies or hanging around the bad part of town.
But as a concrete, practical matter, my 8 year old does not ride the school bus anymore. It is just too rough. I am not going to let him ride the bus again until he has developed some skills. It is a lot of trouble to change my work schedule around and pick him up from school, but it my responsibility to to protect my son and to teach him to defend himself.