A simple question, seeking a simple answer: At a high school gymnastics meet, do all participants have to do all events? Or could you for example have team members that just specialize in one or two events and then don’t do the others?
If the answer is “no, they don’t each have to do all events”, is there a minimum size of team (aside from 1) where it becomes “yes”?
No. At least not when I was in gymnastics. Even in highschool Mark Sohn was Jesus on the Pommel Horse. He never touched anythiong else as far as I know. If there was a way to walk on water with the pommel horse, he did it.
I don’t know what the time on my edit window is but I wanted to add that at the time, I’m pretty sure there were rules about competing in individual events in international competition. I’m pretty sure that during the Olympics you were still required to compete in the all-around and that is one reason Mark Sohn is a relative unknown to many gymnasts. In 1988, he would have been a candidate for the gold on the pommel horse even with the superhuman Soviets that were competing. It wouldn’t have been a guarantee though, because the Soviets at that time (in fact throughout the 80’s) were essentially uncontestable.
Had the Soviets not boycotted, there would have been no American golds in '84. Not one.
Is it the same in both boys and girls’ gymnastics? I should have specified that I was asking about girls’ gymnastics. (What gender are you?)
Male gymnast all the way. Probably my intimate knowledge of obscure pommel horse competitors should have given that away.
I have no idea about womens gymnastics. I’ve never heard of a female event specialist. That is probably because, as you suggest, it is not allowed.
Well, I would hate to assume…though I thought it suspicious enough to check. 
Hey, don’t look at me; if I knew enough about it to suggest anything, I wouldn’t have asked in the first place.
My son did one year of gymnastics as a senior in high school (for a P.E. credit) He usually only did pommel horse, as he got better, he did parallel bars.
(I was happy that he never had the lowest score and his scores improved throughout the year-on the 10 point scale, he usually scored in the 3’s!!, but golly, he had fun!
The competitions issued individual medals for 1st through 6th place based on total points. So the more points you got, the higher you placed. So it follows that the more events you did and the better you did them, the higher you placed. I think they also gave out medals for individual events. And they had some system set up for awarding 1st, 2nd, and 3rd place for the school team scores based on the number of team members and their scores.