PR style = best style
You aim at the person and its name shows up. Depending on the range, the player's name takes faster (the closer) or longer (the farther) to show up.
i.e. If the person is 500 meters it could take maybe 5 seconds for his name to show up, but if he is 1 meter away from you it could be instant.
Also you don't necessarily have to aim with the gun, as long as your mouse is aiming at the person, be it with knife, fists, binoculars, etc., his name will show.
Maybe at first it should not be so that the enemy can hear you, this would make things simpler and easier for everyone. I think that there's still shouldn't be a "Squad" chat, but just "Local" so that everyone near you can hear you.