I think the stealth system in GTA Online is really neglected.
I would first change the stealth system that we have currently.
- Silencers wouldn't get cop attention
- Stealth mode removes your blip on radar
Then I would add in other stealth options.
- Add in a "Contract" option when you call lester. It would be basically a bounty, but the person who the contract was set on cannot see it.
- If you get 50 stealth kills, your blip would become 50% transparent on the minimap by default. But regular kills (npc's or players) would bring you back to opaque.
And finally, more dlc's.
- Ability to duel wield weapons like in SA
- Ski Mask
- Bar code tattoo
- Stealth Helicopter where it is virtually soundless
I think a Stealth/Assassin system would bring a fresh feel to GTA Online.