I will have more time to elaborate on this later as I'm kinda rushing to post right now but a feature I would like to see in the game when Carlo becomes a Made Man are a set of favour missions that are given by a variety of characters from Liberty City's non-Italian underworld. Collecting debts, mediating disputes, intimidating witnesses, silently taking someone out of the equation... that grade of thing. You'd earn special one time perks for each favour you complete. What do you think?
Everything else you outlined sounds fantastic. Good job.