This doesn't change much throughout the game, but I wouldn't really call that the "hacking" part of the gameplay as its pretty much only done to trigger a cutscene (at least when Marcus has to hack into it himself). As for pipe bursts, trigger them when they're in front of you and they'll go off only when a cop drives through it so don't worry, you and any other civilians will be safe driving through them.
Hacking gameplay to me is using the cameras, and environment to incapacitate,distract or eliminate the enemy but I do agree that it can become incredibly slow when using drones, especially when they break and you have to wait for them to recharge.
But generally before I go into an area I like to have all the enemies removed so what I do is arrest all those that can call reinforcements, and try to take out the rest using stuns, explosives, etc and if things get hectic or there are just too many or its a situation where the above wont work then I call in a gang hit. When there are a few or no enemies left I'll sent in Marcus to get the objective. It takes a hell of a lot of patience and time but I found it to be an enjoyable way to play them game.
I played one of the later missions using the grenade launcher and that was a hell of a lot of fun too so I'm considering doing a lethal second playthrough.
Looking back at it, I understand why people say it's weird for Dedsec to use weapons, in any other situation you'd be considered a terrorist and it is strange for a hacker group to have snipers and grenade launchers. But I don't think that they should remove weapons entirely as it removes gameplay variety and replay value along with shrinking your audience. On one hand I'd be okay with them toning it down and having less extreme weapons available, like there's logically no reason for them to have grenade launchers, snipers and assault rifles. But on the other hand, if you get caught you get shot at and you should have a way to defend yourself, america allows citizens to carry guns and most importantly, it's just fun. So I'm not sure what I want in regards to guns in Watch_Dogs 3 but I still say they shouldn't remove them completely.