Will learning about historic events hurt him mentally??

well my non profit has begun an afterschool group to get the higher functioning kiddos together to playgames; talk; do teen things.. cooper was very angry about me making him go.. kept saying he wants things to be "normal" .. which means he doesnt want anything new in his routine. I told him he could be brave and do this for me; after all I have been taking him to swimming every Tuesday night and I'm sure I'd rather stay home and do something else if I really wanted to.. he quickly decided he'd try it this 1 time. he was ok when I picked him up; very stimmy; scripting a tv show and waving his hands around.. so he went out front to have some quiet time before getting in the van with siblings. He said he would be willing to try it again; since they decided to go see Alice In Wonderland 3d at market commons this weekend.. he is seeing there are others like him and it scares him.. some have different "stims" and he doesnt quiet know what to do when they "go off"... we are talking about how everyone is different.. he says he doesnt like different people.. which is funny considering who its coming from.. lol
he has begun swimming for speical olympics every tues night for an hour they practice. he competes in competitions around the state; depending on where/when and if i can get away for a night to take him and find sitters etc.. they are on weekends; but when your husband works sundays it doesnt always work out. he swims backstroke and is pretty good. he has won several gold medals over the last few yrs and says.. "its what I do".. he refuses to consider any other sports as an option. he had to make adjustments because the usual coach has been out the last few weeks (lady) and he had to adjust to a man coaching and not really knowing him at all. he cried; splashed; was mean to the other swimmers; I pretty much leaned over the observation deck and reminded him.. we can leave and not come back at any time.. i know you are upset and scared of someone new; but we need to be flexible and it will be ok.. she will be back when she can.. she has many things to do as well as help you swim etc... he pulled himself together and was fine this last week when she didnt show up again.

he has a huge test on Africa - regions; temperate zones; rivers; religions (Islam) and who fouded it and so on... crazy for me to try to explain it to a kid that barely realizes there is another part of the world when he is in his own little world.. its one of the many things I struggle with... how much is too much when including him in "normal regular ed.?"... I mean this was our goal all along.. to keep him mainstreamed until he ages out at 21... but in the mean time he could care less about Africa and religion and 1000's of year ago.. he lives in the present and most kids can not fathom 1000's of years ago, let alone slavery and things like that.. yes it's history, but do I really want him to know and be scared of the events that he is reading about? some of the things are horrific and he cries about what people did to each other and if they can do it to him or me...

its a double edge sword... yes he is learning with his peers and taking tests and pretty much passing them and keeping up.. however, I'm wondering if it is affecting him mentally; psychologically?