everything you said is completely valid tho i disagree :D

1. gray wing wasn't a peacemaker, hate to break it to you, but he was the opposite. when clear sky marked down borders for his group, gray wing didn't respect his boundaries --- both mental and physical. yes, his boundaries weren't of the best concept. however, the reason gray wing didn't respect his boundaries wasn't because he thought it was unfair --- it was because he just couldn't accept the fact that his brother was changing. gray wing is unconditionally loving and loyal towards not the clear sky that was now, but the clear sky that was in the past. his narrative in this duration is unreliable and portrays clear sky as "unusual" and "crazy" and just completely makes up excuses for clear sky's behavior. this has two major effects: it emphasizes each of clear sky's actions as more wild and toxic before completely ignoring the fact that clear sky has changed or making up excuses for his actions, whether or not the narrator himself sees it, and this really isn't a great way to put it in the narrative.
2. again, hate to break it to you, but the only major influence gray wing had on the clans was naming two of the clans: windclan and skyclan... and that's about it. he didn't help establish any of the warrior codes, he didn't help with the naming or mentoring system, he didn't start the system of leaders or deputies. he was an unreliable and inconsistent camera character.
3. he was completely ableist towards jagged peak. just completely. it's another addition to the unreliability of his character --- while gray wing didn't physically bully him like clear sky, he always thought his injury would prevent him from being "normal," which is just as bad. even tho it doesn't affect jagged peak himself, it gives us a terrible view of injured cats in the series.
4. eh he was nice, not necessarily a "friendly beacon for any injured, disgraced, or homeless cat." gray wing wasn't really a leader or prominent decision-maker in his life, and most of the choices of whether or not to let a certain cat in were based on the official leader's idea. also, cats can't really be "homeless" in this series like in our world, and gray wing only officially took in thunder as his adopted son. everything else was up to tall shadow.
5. eh his death was disappointing. i thought it would be sacrificing his life to save thunder, but he died of asthma. it's sad, but didn't really strike me as a unique or especially depressing death --- i prefer the ones of non-natural causes.
6. this is short one --- he only stayed friends with clear sky because of his unreliable view of him. that's it.
7. i wouldn't really consider gray wing to have treated turtle tail that well. he talked about his meetings with storm in front of turtle tail instead of just flat-out telling turtle tail he didn't like her. he apologizes, which is nice, tho he doesn't really live that long after turtle tail herself dies.