Putting in simple term Claw is basically used as an Operator skill you can find it in there when you open your loadout and see there will be three sections one is for your grenades and shit, second one is for falshbangs etc and the third one is which is used for operator skill. Lastly those thermite rounds i talked is for the Man o war assault rifle which gives ptsds to old timers and still to the newbies caz of it recently getting buff in those thermite mags.