Tee one thing you mentioned that I can definitively comment on is the competition against teammates. At my school, we also follow the notion that teammates should not compete against each other, especially since we roll against each other all the time. I've never seen an issue with it, and neither do any of my teammates since they usually decide the outcome of a potential match-up with a coin flip or something similar.
I know that one of the most talented teammates I have forfeited a match he had in competition against another teammate of ours because he was fighting outside of his normal weight class. Since he had decided not to cut weight for the competition, he felt that he was outside of his normal division and that forfeiting to a teammate who had always fought there was the right thing to do.
However, this issue is always up for discussion. I personally see no problem with it, but I can see it becoming concerning if your child is competing and there is barely anyone in his division. For instance, if there were only four people signed up in his division and one of them was a teammate, then he would only have one match. The way I see it, I just follow protocol and it seems logical to just show respect by not fighting teammates in competition but if it's something you have an actual issue with, then bring it up along with your other questions.