I am through the game now twice and never had there been the situation where I got trouble in whatever kind of way because one knocked out dude was revived again. In fact, I still used his body to lure his friends over, so I can tase them down as well. Works very good and it gives me more xp than killing, which is the point. Killing - for me - is totally useless and inefficient, because I am either hiding the body well enough or if someone else saw the body, I knock him out as well. No need to waste xp with killing, in no situation.
That depends on how you play. I was mostly lethal and did most of my killing with a silenced pistol and enemies rarely heard my victims.
Of course it depends on how you play. But the nature of men is to farm as much xp as possible, especially if it's so easy.
I stopped this behavior after I had maxed out all the augs I needed... which is too late, imo.