What potential? You won't notice a saboteur until he comes into your crosshair which makes it turn red, when that happens unless you're quick or careful, you're deadmeat.
As for the snipers, they're FAR from dominant in the game, because so often you can simply hug the wall and there are lots of cover to go from, there are tons of tight corridors and enclosed indoor spaces where as a sniper you can't just sit there, it's harder to aim with the sniper scope than through the scope of the standard AR, a sniper's view is more restricted, they're quite vulnerable to being blindsided as well as they're weaker when it comes to close-quarters shoot-outs. Often you can pick off snipers with the AR from afar because he's too focused on some other sap. If you make the snipers weaker they would be useless. In general only the really good snipers are successful, as with most of the classes in the game, you're only successful when 1) you're skilled, 2) you're a smart player and 3) you're playing against a weaker team.
You're making complaints based on what you imagine things to be but tbh you really don't know jackshit about how the game plays, especially how balanced things are.
