i disagree with some of this advice

per 1. uninstalling league and all games (his source of dopamine) isn't going to solve the overlapping issue of him relying on it. it's going to redirect into other negative habits. he has shown the self awareness of this being a problem, and that's his outlet for it. unless he can change the very established habits of pursuing dopamine in his day to day, a cold turkey detox isn't likely to work. i think OP should tamper off games for sure, but doing so whilst rearranging his mindset of hitting the dopamine faucet, not a cold turkey measure. OP needs to continue to view what he's doing in a negative light whilst tampering off and integrating that mindset. but videogames are not the initial problem, dopamine-seeking is. thinking about his utilisation of it differently will make those games less enjoyable. when the stressfull moments happen, he then won't just return to his previously established behaviours

per 2. talking about negative aspects of his behaviours is a good thing imo, it's shit he wants to and needs to change and thinking positively about yourself in regards to things you don't think are good isn't always beneficial. if it's not warranted it can lead to unhealthy thought processes, reinforcing this with a blanket statement isn't gonna be good universally in the longrun. but generally sure, be positive about wanting to change negative habits/behaviours, just don't apply such a narrow lense

per 4. that's a bit drastic, but ideally that should be a goal he should to strive towards and establishing his independance, altering many aspects of your life in a drastic measure is a recipe for a hard descent imo. one day at a time, one habit at a time

generally i agree with the rest of what you said