Don't forget , your project will attract only few people !
I remember playing Armed Assault , and after a difficult progression, i stoped, caus of it's simulation factor.
One , or two shots and sometimes you are out and you must
retry from your last safety save.
I abandonned, the goal fo FPS game is to have fun.
There are games that allow for example to adjust difficulty
when you retry, or some rare games using auto balancing difficulty depending on how player plays !
Well only few people will be attracted, caus they don't care to be frustrated , or to not have explosions, fun etc ...
Well it was just my opinion about realistic Vs Non realistic and fun.