operatives ... cannot atrack in any way or they lose there disguise. (I think this also applies for using abbilitys)
I believe Operatives can hack stuff while in disguise.
or is it like cod which is similar (when stabbing not slashing) but its faster, wait do you stab when knifing or it is only in singleplayer/nazi zombies?
COD has both a slash and a stab move. The stab is usually referred to as "commando-knife", because this animation is played when you lunge towards the enemy (if using commando, you can practically lunge farther than the OHK-range for the SPAS-12 is). And thinking about it, the "commando-knife" animation from COD is very, very similar to the melee-animation from Bad Company 2, only about 3 times as fast.
i know from the Freedom of movement vid in Features on their site at the slide part he runs around corner and pistol knifes
There is absolutely no combat involved in http://www.youtube.com/watch?v=Gt63OGq5G7M?
EDIT: Found http://www.youtube.com/watch?v=uGBUssSP0g0t=50s you were referring to. Fun fact: We can see a double-wall-hop in that as well.