All of that! The Beasts themselves are NOT your generic alien species that want to kill everyone for potato reasons, they are powerful pokemon that are in an alien world and react exactly as you would expect one to react in that situation. (Walk a mile in there shoes, you would act exactly as they would.)I don’t mind what the anime did with the Ultra Beasts, as most of them aren’t inherently evil. I looked them up and saw how they were created, and they were based on the idea of invasive species. The thing about invasive species is that they aren’t evil on their own, but the situations they create by their existence can be problematic. Therefore, most of the Ultra Beasts are just confused and unfamiliar with the world of Pokémon, and the anime can treat them more lightly, as they aren’t intending to cause harm.
The only two Ultra Beasts that are evil are Nihilego, which is based off of a parasite, and Guzzlord, who will do literally anything in order to get his next meal, even if that means destroying towns and reducing the landscape to a wasteland. Because of this, the anime has taken Nihilego really seriously, and it’s looking like the same’s going to happen with Guzzlord.
They are still a problem for those around, but the beast HAS no ill intentions outside of the lives they are use too.
As for your two exceptions.
Nihilego, unlike the other beasts, are not even sentient and act on instinct, they cannot be reasoned with. Guzzlord would act like a puppy if they go with a comedic route... but that is where the comedy ends, their biology is built around eating everything and their world is a hell hole even for them.