You bring up some good points but they did not ask me about the psychological impact nor am I an expert in this. If I were to offer my armchair commander opini

You bring up some good points but they did not ask me about the psychological impact nor am I an expert in this. If I were to offer my armchair commander opinion on that topic it would be to limit the amount of time the child is permitted on the system and to limit what multiplayer games are permitted to keep them away from abusive people and most importantly to be with them as much as possible and avoid the risk of the gaming platform becoming a baby-sitter. I trust in good faith that the person asking the question is a good parent and will spend as much time as possible with their child and maybe even join them in playing some of the games, as they are only a child once. There are ways to automate some usage limits in Linux/Unix. One could use PAM limits to prevent logins to/from particular times of the day/night and to limit how long one may be logged in. These limits should be explained to the child so they are not as upset when the system logs them out. Perhaps find a way to put the system to sleep so that unsaved game progress is less likely to be lost.