It was always my interpretation that Lore had acquired the ship long ago. He was on the Enterprise for all of 5 minutes before he decided to get them all killed, I doubt the Pakleds would've faired much better.
Were the kids on an away mission? I thought they had gotten to the poisonous plant in the ship's arboretum? Anyway, I agree the B-plot there was weak, I'm not sure why I'm supposed to care about these kids or see the parallel between them and Data/Lore.
In the case of the kids the older brother pulled a joke, the younger took it too seriously and ate some stupid poisonous plant putting his life at risk. (Curing unknown alien viruses inside of a day? Piece of cake for the Enterprise medical staff. Producing and providing anti-toxins for known poisons? Yikes! Need to get to a starbase toot-sweet!) I mean it's a fairly "common" brother thing for shit to happen like that.
Data's case? Very, very, different. Data doesn't owe Lore an OUNCE of forgiveness given that Lore has shown him self to be a complete sociopath who doesn't care about anyone else but himself. He nearly killed the entire Enterprise crew and violently attacked their "father." Sorry, why does Data owe Lore forgiveness? What differences do he and Lore have to reconcile? Seems like Data's in the perfect "fuck that guy" situation to me.
I agree that if the idea was for the line about forgiveness was meant to apply for Data and Lore then that's a messed-up message. Lore's a mass-murdering sociopath not a guy who broke Data's favorite toy when they were younger or something.