I cannot speak for others but there are problems:
1) In Watson is a corner street fight between two cops, and 4ish gangers (dont recall Maelstrom or Scavs) - SO many times I help the police and shoot the gangers, holster weapon but immediately become hostile with the police.
2) The idiotic dynamic of standing near someone potentially hostile triggers hostility. If you merely stand on the sidewalk , in the flow of pedestrian traffic mind you, not crossing a police line (this also works for gang members) - just standing along with other civilians makes an automatic Yellow to Red hostility system - you could be just standing there on the phone or looking at map. So you become hostile for no reason - no matter how much the police/gang likes/dislikes you. Again, this is just standing with other pedestrians with weapons holstered - I don't mean approach/get in face/draw weapons.
3) As cars can be quite loose in handling - especially if you are driving with mouse and keyboard it is so easy to jump the curve on a tight turn and civilians either sometimes dont even try to move or crouch down and put their hands over their head to a car coming too close. This can devolve into a quick pick up of police stars, combined with magical teleporting in cops and drones you have an escalating situation.
I do not think its fair to state everyone with a problem just wants to go shooting up the town. I seriously wish there was a reputation monitor with groups so the NCPD could see you - see you are a sub-con in good standing, etc and at least say hello
the cops/gangs aggroing you for standing around them too long is on purpose. NC is a rough city, and irl in a non apocalyptic NYC, standing or staring at some tough guy will lead to something similar. As long as you keep it moving its fine. This is actually very accurate. The Guns are pulled faster, but this is a world where a cop shooting an appendage is considered a warning shot (news bulletin in game)
Yes killing pedestrians is something that should cause problems, and yes when someone jumps a curb not everyone successfully picks the best escape route. freezing is a natural common response to panic. You don't have to drive, and you don't have to drive fast, irl, trying to take a turn, or driving fast when you don't know where you are going is likely to lead to accidents. you are supposed to be going like 15-20 mph on a turn irl. In game, we are often driving recklessly.
also, this depends on which vehicle you drive and how good you are at it. bikes handle easier from what I have played.
but back to original point, killing civilians via car should lead to drama.
playing with Guns, I notice aggro is much harder to control. I look at this as a feature. Anyone shooting a gun around you is a threat. Accident or not, bullets kill. The cops react to who the bullets hit, who it scares, and how much disruption/property dmg they see. Use melee around cops, and you get a lot less aggro. One game I was going to use tons of grenades, almost every encounter police would eventually get involved if it wasn't a mostly abandoned/seperate area. Not surprisingly using grenades often is chaotic and likely to attract attention. If you want less drama, stop using Guns. Use more takedowns if you want controlled response. If you use Guns, do it very carefully, think about getting silencers, shooting through walls is likely to cause extra drama. be conscious of shooting out into peoples directions.
This is not accidental stuff, this is what id expect to happen in a rough area if you do these types of behaviors. And to me, this is the extra gameplay effects police are there for. To make you consider how you approach a situation, and make it slightly more difficult/chaotic to go in Guns blazing in populated areas.
