Something I've always found that brings the gamemode down is the insane levels of crime. This included Diggy's MetroRP, where there we only really a few types of people: The petty theft, the apparently "experienced" assassin with the big overpowered SMG or sniper rifle, the policeman who didn't do much and wasn't really going to be a policeman for any longer, and the shopkeeper whose job was to sell rocket launchers at varying prices.
I've already discussed this in pretty great detail.
1. Law enforcement jobs are the only professions that have weapons upon spawning.
2. Jail terms are significantly longer.
3. Weapons are much more expensive.
4. People who have committed felonies may not buy guns, unless the Mayor allows it.
There's also a bunch of other fairness checks, like people who are wanted cannot Ctrl+K (which teleports you to spawn now).