I watched it and while it's nowhere near as bad as MatPat's, it still gets a lot wrong.
I actually always got the impression that Rosalina had PTSD or something similar, but, only in the storybook. I thought the entire point of the storybook was to show how she had it and how she overcame it, with the secret ending of Galaxy depicting how she can now visit her home in peace since getting over it, or at least to get "that one chance" to mourn for her family every 100 years, that being the one remnant of her past life in her current life.
Besides that he got a lot of things wrong. Hungry Lumas often aren't actually legitimately hungry, they're more like Kirby in that they just love to eat, it's pretty clear from their dialogue, and even by how some of them even resort to selling things to get their goods.
As for the whole "not stopping Bowser despite clearly being capable of that and far more" thing, that's literally just due to the fact Rosalina, as a main character, was a late addition to Galaxy. While it does confuse me WHY she is so blatantly over powered yet rarely decides to use it practically (and they even imply that Bowser knew how powerful she is too), and I do think it would have been smarter for the story to just not make her so blatantly powerful (though I ultimately think it makes Rosalina herself a way cooler character with way more potential so I think they picked the lesser of two evils), they didn't go that route and as such we end up with a "why doesn't Mega Man just teleport TO the Robot Masters?" situation, in that we're just supposed to shrug our shoulders and just accept that they did this to make sure we still have some excuse to have Mario go on an adventure through space, while still having a god character with infinite power or whatever just sit around. And it's moot anyway since, at the end of Galaxy, Rosalina DOES step up to fix everything anyway when she does the universe reset, and before that, ravages Bowser's fleet.
There's more I can pick out but I won't waste my time. Y'all don't care anyway. :V