If you play multiplayer, then "IFAK fully restores player health" and "IFAK fully restores AI health" I recommend turning it off. Because in this position system is complete.
But if you play a single player game, this is not necessary.
Regarding the other settings ... the standard settings are the most optimal, in my opinion.
About suicide. Needed for multiplayer) When your comrades cannot save you, you can kill yourself) This is unrealistic, but necessary for gameplay)))
And about "AI kills the wounded", In ARMA, there is nothing to do with the prisoners. Therefore, it is better to enable finishing. If we talk about real life, only regular troops take prisoners and then, not always. Intelligence or special units not take prisoners, because it will interfere with the main task (Of course, if the task is not to take a prisoner).