Well, I am not too close (I don't live there anymore) :-).
The Gauld's have always been financially stable, at least as far as I know.
Malcolm will be forever Malcolm, the idiot son of a tyrant. I was never quite convinced he actually wanted to run the school, marry Laura etc. I think it was just a matter of him not being able to do anything else. Joe was always king, Joe was always the 'prophet'.
Interesting choice of words. See, in my time, Laura Denton was groomed for this job. She was the most publicly sympathetic personality who could suck in the public with the possible exception of Michelle Correa.
But Michelle was not stable. She had glamor, could generate irresistible interest, but she could turn on Hyde and disappoint by seeing to her own interests and needs... which she did, upon leaving Hyde, and ultimately died in a motorcycle accident, from what I hear.
Joanne Wingood was another candidate, but too no nonsense, and had no interest in Malcolm anyway. Note that she did go on to head Hyde - DC for a time, and is now, from what I understand, head of Hyde - Bronx.
Laura bought the spiel, expressed herself passionately, albeit with a much more limited vocabulary at that time, and was reasonably emotionally stable. She was perfect.
I remember that my first impression of Malcolm was that of a well-meaning do-gooder. He was still at Bowdoin, or perhaps had just graduated, and had not a headmaster-oriented thought rattling around in his skull. He was more interested in hanging around with his pals than entertaining any thoughts re. following his father's footsteps. I find your impression of his ambiguity utterly believable.
Pray tell, what caused you to return to Bath? Did the school wave a flag of 'golden opportunity' in your direction? I did know someone from my time, who accepted such a flag for a summer, and who was quite disappointed with the reality of that political climate. It did not comport with their impression of what Hyde was all about. But then, they had not experienced it like some of us did, they being one of the 'chosen ones' at the time...