that's a good idea. it makes me think of Need For Speed's heat system in Carbon where the more crimes you commit in one area the more police patrol there and the more likely you are to get wanted when a cop sees you. it also means when you are pursued and move into a lower heat area I think the police go easier on you.
this could work well with a map with multiple cities as realistically one city's police department might not have a record on a criminal in another city, although the FBI would always recognise you.
this kinda shit could change depending on difficulty level obviously. if you don't want police like that you could go to easy mode or whatever.
Adding on to this if since it would be safe to assume that proper stores will return in SR5 then it would be nice if say for example you rob a bunch of stores in the area, each time that happens it increases the risk of the store owner pulling out a weapon to try and defend themselves from the Boss (typically with a shotgun, machete or a sniper rifle).
It would also be pretty nice if enemies were more intelligent when in combat and used actual tactics. Because brain-dead enemies in Saints Row is an issue dating all the way back to the first game where enemies would often stand right in front of the Boss while shooting or lob grenades or shoot a rocket at their own comrades. I've even seen the AI try to shoot the Boss through a car and the car exploded in their faces.
As much as some people hate the idea of Volition taking anything from Rockstar's book in this case it's for the better.
When in combat enemies will try and take cover not just behind cars but other objects excluding explosives.
When an enemy is near death they will sometimes fall to the ground and continue firing at the player while being dragged to safety by an ally (similar to the Last Stand mechanic used for the enemies in GTA 5 or any of the Infinity Ward COD's)
Use SR5 as an opportunity to revive the scrapped parkour mechanic from SR3, and let the AI use the same parkour abilities as the player.
Have the AI tip over objects such as hot dog stands, dumpsters, and tables to use as makeshift cover.
Make the enemies more audible during combat outside of death screams. (Similar to say the first two Destroy all Humans games where enemies will never shut up before you put them down).
Have enemies rappel down the sides of buildings.
Bring back the dual Notoriety System from SR2 albeit with some tweaks. In this case for enemy law enforcement regular police will be deployed at level 1, cops with better weapons at level 2, sheriff deputies\ATF\Blue Jacket FBI's\Highway Patrol at level 3, Riot Cops and SWAT at level 4, Ultor Masako and National Guard Units at level 5 and finally STAG and FBI SWAT at level 6.
As for enemy gangs players should have the option once they've defeated a gang to relinquish control of a Neighborhood back to said gang. (Similar to the systems used in Far Cry or Just Cause 3)
Have certain units like tanks or enemies with RPG's be a rare sight. It was extremely annoying in SR3 and SR4 when you're fighting a bunch of enemies and all of a sudden the fight ends because some assclown with a rocket launcher or a tank decides to blow up\run over their own allies.
Have the enemy factions change up their tactics depending on the scenario. Is the Boss wiping out a factions motorpool? Have the enemies start spawning from roadblocks instead of deploying a car every 5 seconds. Is the Boss using nothing but shotguns? Well throw in a curve-ball and start deploying snipers on the roof. Is the Boss hiding behind cover? Start chucking grenades, molotovs, pipe bombs and tear gas canisters their way, also have enemies actively chase after the player if they start fleeing.
On the flipside if you wipe out a large number of enemies in the area then any other opponents left alive will start to flee and the notoriety meter for that faction will be reset back to a low level. (Level 1 or 2) This would be a lot less like the notoriety system in SR4 and more like the wanted levels from Just Cause 3.
Going back to the parkour mechanic have it to where players can access the rooftops and have enemies spawn on the rooftops. (Think a cross between Watchdogs and Crackdown or Infamous)
Bring back the destructible environments from SR2 but with added gameplay features. For example the sparks from a destroyed sign will electrocute enemies or set them on fire, you can destroy balconies to quickly take care of snipers, car gibs stay in the area a bit longer, and most importantly destroyed objects should stay in the area much longer instead of immediately fading away like SR2.
Speaking of SR2 bring back the ability to use objects in the environment as weapons. For example beer bottles, chairs, lamps, street signs, mailboxes, hedge-trimmers etc.
Last SR2 related thing is bring back the fighting styles and finishers from SR2 and the sprint attacks from SR3.
Make the NPC's more talkative and vivid in general and by that I don't mean have half the city's population dress up as gimps, strippers, ninjas, and furries, I mean actual interaction and dialogue. This is where games like Destroy all Humans, Deus Ex, Postal 2, SR1-SR2 and yes even GTA excelled at.
Speaking of which have random events occur in the city that effect the gameplay in one way or another. (Sports games, concerts and conventions will bring a massive number of civilians and cops to the area of the event, during a heavy storm almost no NPC's outside of cops, gang members, taxis, and emergency services will spawn, civilian and military parades in the city's downtown district, cultural festivals in the more residential areas such as the Barrios or Chinatown, and of course the rare chance of more violent events such as police raids, riots and gang wars.)
Let PC and Console users change the appearance of enemies using the NPC SDK Tools.
Bring back the Specialists System from SR3 for each of the enemy gangs. (Other users can chime in for ideas on the appearance and tactics of the Specialists)
