I'm only going to address armor seeing as hit reg won,t matter to me until the servers are Properly online, for one, and since this is interlocked with everyone's personal connectivity, well, results may vary.
As for armor... Any shooter with armor and ambitions of realism will hit this question sooner than later: realism or fun? I call it the Tarkov conundrum.
If armor is realistically powerful, but does not cover the whole body, a meta will appear, for example: Tarkov's leg meta. Currently, I've been testing out shooting people in the abdomen in WW3. To be honest, I see no value in headshots anymore. It's the same situation as with Tarkov here, and it could be by design to be honest. I've adapted to it and a lot of other players have too (I'm seeing a lot of deaths from 100 dmg to the abdomen). I now run around with no armor and aim for the abdomen and my results have been extremely positive. I see no difference in my survivability but I get more kills (less people escaping after being shot up).
My suggestions to the devs would just to be clear what the priority is. If its realism, keep tweaking but expect metas to appear. If you want to avoid that though, my simple suggestion would be to have armor values apply to the whole body (only separate head and the rest of the body). types of ammo won't matter if a shot to the abdomen is always considered a flesh hit... the meta will just be aim for the abs with the highest flesh dmg ammo in the game, skip armor piercing. Its counter intuitive, but this is a game, played by gamers. Gamers always go for the most effective solution. Realism, and sometimes even fun, be damned.