Far Cry's sniper scope sway is actually just the right amount IMO. There are plenty games that overdo it. My only problem with the sniper scope in Far Cry is the lack of a definitive and easy to see cross point at the center of it's crosshairs. There are ways to overcome any lack of success you may be having with the sniper rifle though, at least in sp anyway. There are places to shoot other than the head which are one shot kills. Mid torso just under and above the armor work well too, I have several videos to prove it.
The lack of an easy to see cross point on the cross hairs is largely why I use such body parts to aim at. In a pinch I have been able to get off a few shots quickly panning from one target to another even while hangliding and using minimal zoom by hitting such spots. Oh and btw, besides using the Spacebar to hold breath and steady/add zoom, the stamina bar degrades as you use such a feature, so make sure it's not maxed out or the scope will spring back to swaying.
If you ever have the opportunity to use such a powerful scope, in real life, you'll see that the drifting is pretty normal. Some games are really unrealistic in their "steady cam" scopes. Try hitting a target at even 300 meters, after running with a 40 pound rucksack, and you're tired, hungry, there's a humid haze...well, you get the picture.
Well yeah, obviously this game and many others don't take into account many of the real life factors of movement, heart rate, breathing, etc. When I said it's just the right amount I meant for a video game to be practical, not that it's equal to real life.
In reality if you obsess over realism too much in games you forget that you're already at a disadvantage with much less peripheral, using abstract controls rather than hands directly on weapons, vehicles, etc. Can you "squeeze" the trigger vs pull it, nope.
Also, the hearing can no way be as good as real life even with the best sound system. Add to that the fact that elite soldiers can even detect things by smell, and you have just a few of the many disadvatages playing a battle in a game has over actually experiencing one.
That said however it does depend greatly on the person who's handling the real life weapon and what he's using to steady it. I tend to think also that any sniper who's sole job is sniping would try and avoid being out of breath with a high heart rate when he's taking critical shots.
Where the game gets over the top is how you can shoot the sniper rifle while not prone, even flying a hang glider, though trust me, it's by no means easy. It's fun just the same though, and that's all a tactical shooter needs be as long as it has some semblance of realism.
The Stealth meter seems to be designed to sort of make up for the loss of peripheral vision - however, I hardly ever notice it especially when my eyes are glued to the screen.