After reading all your post I came with my conclusion.
I would have it so that you can you can choose from a group of classes, each containing one primary & secondary weapon and of course the a stealthy little knife

. And you would have the ability to pick dead enemy weapons, as long as you drop your current primary weapon. But if you are a medic, for example, and you picked up a sniper rifle, it would be nearly as steady as if you were an actual sniper.
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Pain is temporary. Pride lasts forever.