criminals, bookies, and fences

I like a lot of your ideas for a crime pack. As for horse racing / jockey career, I don't foresee that being something that could be implemented because its a significant gameplay element that would rely on Players needing to have purchased the Horse Ranch expansion to experience. However, I do understand the use of this aspect to introduce a form of gambling as a crime element. Maybe a table-top horse racing pub game could be an alternative way to implement your horse-race-bookie idea, where Sims can place bets on the game's outcome. To "fix" races, you could use the Handiness + Mischief skills to tinker on the game object to rig the outcome.