Edited Dec. 19, 2020 at 3:40 a.m.
The Kings future is bright, but they're not there yet. I think they have most, if not all the pieces to become a contender again, but they're all still making their way up through the developmental leagues.
I don't disagree with any particular point you made, although I agree with @ZiggyPalffy
that I don't think Petersen takes the reins from Quick just yet. Quick's play hasn't dropped off as much as everyone suggests. He had an abysmal start to the 2019-20 season, but after Christmas, he put up some stellar numbers with a 2.27 GAA and a .923 SV%. I think Petersen has the tools to be the goaltender of the future of the Kings, but I suspect we see Quick as the starter this coming season, split time in 2021-22, and Petersen taking over the starting job in 2022-23.
The nice part about the Kings depth and roster situation is that they will be able to use their expendable assets to acquire pieces to fill gaps. They're not doing it now due to the impending expansion draft, but once that passes, they will be in a position where they will be able to trade some of their numerous assets to acquire quality pieces. The biggest areas of concern are top six wing and 1LD at the moment, but both of those should be easy enough to fill through a combination of weaponizing their cap space and moving a quality center prospect or two.
Last I heard about the OHL is that they're currently working with the provincial government of Ontario to come up with alternative options to the non-checking rule. I honestly think that they would work out a way to play their games outside of Ontario before they put on a league with no body checking. I don't think that's really going to happen. Assuming there is a season which includes body-checking, I think we see Byfield play in the OHL. He might get his 9 games (or 6 games if it's pro-rated) on the Kings without burning a year of his ELC, but I don't think the Kings will keep him up for the season.
I do think the Kings will do better than they did last season, but I don't think they'll be a playoff threat. 80ish points and 6th/7th in the division seems reasonable.