I think you might be taking the trailer too literally and reading too much into it. Just because they're marketing just how involved you can be in the pack doesn't mean they'll point a freeze ray at you and force you to make your sims hold their kid's hand through everything. If you want to grind for a character trait and utilise the parent for it, you can. Or you leave the kid to their own devices. I've had kids independently gain any traits I wanted them to have just as well as I've had more hands-on parents influence their children, because I made them be that involved.
Again, if you don't want a sim to help their kid with a school project, just... don't tell them to help. As simple as that. Your kids aren't going to turn out horrible just because their parents are busy. And you don't have to teach them to say sorry or scold them for cussing.
I would only recommend let's plays if you can keep in mind that it's a series specifically exploring the pack, and they will most likely be very involved as a result in order to showcase just that. If anything, consider watching a let's play of a pack that came after Parenthood to see how the pack works when it's not the player's focus.
