Jace's father was this lucky guy who got rich after somehow getting ahold of the diary, but I don't think he was related to anyone significant.
Jace was caught by Superman, and was presumably turned over by him to the police after Superman incinerated the diary.
Not sure about there being any wiggle room with regard to Nigel's death on the show, but perhaps it's a detail you can tweak.
Looking forward to your new story whenever it emerges, CC!
