Optic and Faze are partially known for sniping/quick scoping. They have had one or two guys in competitive matches equipped with sniper rifles on occasion. I just saw Optic Scump sniping in an MLG match. Faze Pamaj announced on YouTube that they were bringing a sniping team to MLG Anaheim 2013. They mostly cover a spot and hard scope but they will quick scope if someone rushes them or while they're on the move.
MW3 had 3 guns
? Nadeshot had a thermal LSW (just watched it on YouTube), I've seen a sniper rifle, FAD, and P90. This video shows the Ump was used heavy, and scanning real quick I saw an M4A1 :
If anything BO2 and MW3 are practically even pro wise. Public matches MW3 got that.
You saying they never played 3v3? You never heard of Game Battles? A lot of pros started there and yes they have a 3v3 tourney.
No, I don't want pro gamers participating in game design. We all played for countless hours but that doesn't mean we know shyt about design. Beta testing would be more effective. Pros are too small of a segment and there's nothing they can say that we can't.