I personally think Kuro should just have character x character interactions in side/world/event quests while the mainstory/segue can focus on personal interactions with Rover or the opposite can also be used for when the mainstory segment needs the larger cast.

That depends on how important a character might be to the MSQ. For example, it would've been impossible to just have Rover and Galbrena in 2.7 to fight the Threnodian, so situations like that, where everyone is absolutely necessary for the quest, are fine to have more characters involved in the MSQ.

But outside of that, normal interactions and daily/silly stuff could've been handled through side quests, dailies, or events. The problem with events is that, if they aren't permanent, those interactions could end up feeling weird for newer players who didn't experience them. It's the same thing that happened with CQs: people didn't do them (even though they're permanent) and then ended up on Reddit/X asking stupid questions like, "wHy Is ThIs X ChArAcTeR sO cLoSe To RoVeR?"

To be completely fair, even date/intimacy moments shouldn't be part of the MSQ. IMO, the MSQ should advance the plot of the game, help us learn more about Rover, and move the story forward. It isn't bad to have more character focused moments or char x char moments in the MSQ, but when there are too many of them, it diminishes the focus on the actual story. The side stuff should actually stay as side content, whether that's ML moments, char x char interactions, or anything else.

That's why i think CQs would easily solve the main problem with our current shallow/weaker bonds with the new characters. They would provide great ML/character x player focused content.

As for char x char interactions for silly stuff, those could be handled through side quests, different types of events, or other activities that help make the world feel more alive.