You know, I really should give this game another shot one of these days; too bad I can't seem to find a copy.
Anyone got suggestions for playstyles? I usually just tried to go full stealth; sneaking around, silence pistol for everything. Any suggestions for a playthrough?
I personally replayed it recently with full stealth too & completed around 25% of the game before even going to Act 2. First & foremost things I recommend are going offline on the multiplayer through options so the griefing retards won't ruin it for you. And complete the cup shell game the first thing you do in the game, you can even cheat on it if you want.
I say this as someone who did 8 Gang Hideouts (first try with nothing but the silenced pistol & only headshots

) without the exp bonus, do this first if you don't want shitty slow progress. Also, side note, do the gang hideouts till the 9th one, you get one of the best guns in the game, Silenced Goblin (the supressed burst rifle). You can literally complete them with the Supressed Pistol (& the Silenced Uzi too if you want) alone if you have the skills.
Speaking of skills, try to prioritize Hacking first & foremost (you'll need it in later missions), followed by Combat (enemies get really fucking annoying with shit like enforcers everywhere, also the takedown animations alone are worth it), Crafting (Grenades & IEDs come in handy during some mission) & Driving skills (you'll mainly want defensive & precision driver skills, there's a reason to prioritise this the least).
I said all that from personal experience as of now. However, you can also go full John Wick mode on it too.
Ubisoft indirectly & unintentionally made the best John Wick/modern Punisher game without realizing, until Legion (which sucks).
I also recommend going for the Watch Dogs Remastered mod for some extra stuff that makes the game more challenging & cooler (having a suppressed sniper rifle is something that should've been in the base game)