Thanks for the welcome! I mostly stick to reading on the Sims 3 forum; me and my kids are mostly the TS3 variety of simmers, and it's been very hard to suss out a good story for Sims 4. My first actual interest in anything was very recent and it involved some very interesting autonomous Caleb and Mortimer, of all people. Then I found out Johnny and Malcolm were supposed to be related and it got me thinking about TS3 Malcolm vs. TS4. He was always a little neglected, even in TS3, and I figure Johnny would have been attentive and loving and just the most FUN big brother ever. Then their parents took away the only person who gave Malcolm any real attention or affection, so Malcolm is understandably bitter toward them (all 3 of them, really, because at the time it probably felt like Johnny had abandoned him). He was messed up by Johnny's departure, I'm 100% certain of it. I think rebuilding their relationship could be very healing on both their parts.
I take a different approach with Geoffrey, in that I had a mother who did unspeakable abuse to me and my brother, but she was mentally ill. My dad, who stood idly by and let horrible things happen to us, was a rational, mentally healthy person, who should have known better. So I figure, hey, an evil person like Nancy obviously has a skewed perspective on right and wrong, so we expect that from her. Geoffrey is supposed to be good and family oriented, so he is, if anything, as culpable (and maybe moreso) than Nancy, because he KNOWS it's wrong and goes along with it anyways. I'm not sure if he really chose her over Johnny's health and safety or if he felt he had to stay with her for his job, but the result is the same.
I love the idea of Johnny "rescuing" Malcolm, because I think he would, especially when he got to a stable place himself. In the runaway situation I put them in, they couldn't leave their home for a while, and Malcolm literally would wait outside the bathroom until Johnny flushed so he could barge in to chat. Johnny literally couldn't eat or play guitar or dance or ANYTHING without Malcolm 3 pixels away, socially un-distancing himself. I figure Johnny wanted to grab his face and say "oh my GOD do you ever stop talking??".XD But they've never had more than a couple of negative interactions before they get to be friends enough that Malcolm seems to forget he's even evil and dastardly and wants to make enemies. He's angry and lonely but deep down he's a good boy.
Anyways, thank you for giving me another reason to play Sims 4.:D I'm inspired to set up my own version of a Big Brother challenge to entertain my kids while we're all stuck at home. Take care of yourself, and I'll be around when you're feeling well enough to update the challenge.:)