I play a concealment operative and I can tell you right now that it gets way smoother with your knife attacks as you get to higher levels. I remember it being very frustrating at early levels you are right about that. You have to learn to work your tactical advantages to your favor to keep knife attacks rolling in. When you say sticky grenade I assume you're talking about the explosive probe, it does nothing until the next attack hits that target everytime you use a flash bang you should be using that explosive probe, or in pvp when someone is running away I find it handy. As for removing the rifle that can't work without getting some form of gap closer. A no energy 30m ranged attack is the only thing that keeps me in the fight sometimes when people are running away using force jumps and what nots.