Ok so I'm not sure if any of these have been suggested before, and if they have, sorry, I don't check forums

Also, everything I suggest below is just a foundation, not a direct "this is exactly how I want it", it's just ideas FOR ideas to stem off of and evolve.

• Headline ticker thing that moves at the top of the screen for everyone like "Cartel a has waged war on cartel b!" or "update 3.141569 added today, check forums for details"
• In game "are you a robot" checks, as this will hinder/prevent hackers who auto bots on jobs and such, if their code is disrupted by a screen/window that checks.
• The top 10 cartels should own a portion of the bank. Essentially, new players who deposit money into the bank, have to pay the current 2.5% fee to "clean the money", but for the top 10 cartels and their members, the deposit is free and the cartel itself gets a portion of that deposit money from these small narco players.
• Outtages and shortages of NPC shops. Sometimes, in the real world, quantity of supplies drop, and thus prices rise. Perhaps implement a similar situation where there might be a few days or weeks where a shop only has a max daily limit of 2, or 14, or 21 (just making up numbers here), which could in theory affect in game economy some.
• Add crafting/combining of items. Perhaps implement a new education course that unlocks ability to get "super drugs/alcohol", where you combine 5 cokes into 1 super coke, which may give the same amount of energy as using 5, but has only a 2 hour booster cooldown, etc, same with alcohol.
• Bring back rarer, uncommon items in a fun way. Maybe add a new calendar event where during that 1 week, you can buy these items in the NPC shops, like the glittering gifts, or a limited time temporary item, etc. 
• Add a giant NPC boss event (like el chapo or something) in the calendar, where everyone can attack him max twice per day for 3 days, and players are then rewarded by : most damage done, most damage taken, least damage done, least damage taken, etc
• Add a CITY Museum, where players can donate to display their lowest/highest quality item, and other players just browse and look
• Going back to the idea of bringing back rare/uncommon items, perhaps you can add a city NPC owned auction house, where people can bid on whatever item the AH has for 24 hours
• Add more consumables, perhaps something like a book that increases your gym stat train gains for the next 30 minutes, or a cuban cigar that halves your active job timer by half, or an item that decreases education length by 1 hour everytime you use it, etc. (you can even tie this back to the combine feature I suggested, and make a super consumable that doubles your active stats by 1.5 for 5 minutes, etc.
• Add pet fighting, players can add their pet to a dog ring in the city, and other players can make bets on who wins, and the losing pet gets a debuff of "no skill usage in combat" for 24 hours or something
• Add a cartel building assignment- Players have to use construction materials to build a cartel HQ building, where you now have the following upgrades for 24 hours - which has to be manually activated by the capo: 1) all members get an aggression bonus, increasing outgoing hosp time by 1 hr while this upgrade is active 2) all members get a stealth bonus, increasing mug amounts by 10% for 24 hours, 3) all members get a speed bonus, decreasing their job timers by 10% for 24 hours etc etc etc etc etc (i ran out of ideas, just throwing random ones out here)
• Change HALL OF FAME, remove the "stats" and "networth", and add to personal homepage instead. If no one else can see who it is, there's no point to having an entire page in HoF for it. Instead, add some visible categories: "most money mugged" "most time spent in hospital" "most defends won" etc etc. The whole point of being a narco in a crime game is reputation, and reputation people can see, brings the fame.
• Add a player operated lottery in the casino, where a player may offer 500 coke/alcohol for the price of 1 ticket entry per person costing 10m each or something, etc, all games are set by diablo to end in 24 hours so it could be either a net profit, or net loss for the host. Host also will pay a 1-3% fee on withdrawing the ticket profits (maybe idk)
• Add bullets to the game for the guns- BUT make them special types of bullets that can do different things in battle like 1) poison your enemy for 5 turns 2) flashes and blinds enemy for 5 turns, decreasing their firearm but not melee accuracy 3) etc etc etc
• Add an update to the prison system. Currently there is nothing tied to it, besdies just sitting in there and waiting. Maybe add a small minigame/npc shop/gym that can only be accessed in prison, etc
• Add more updates to intel. Maybe increase the cap or remove the hard cap of 1200, to where beyond that you can unlock special privelges (as suggested in my other post).
• More to come when I think about it, might make a pt 2

Just an opinion but the dog fighting npc boss ,special bullets, cocaine combination and, cartel build assignment (CBA)sounds like decent ideas, really like a broader choice melee weapons like butter fly knife ,gambit ,or even a kitana be nice