This is something I've always wanted to see, a spray 'n' pray feature. I wouldn't go out and call it as a fact, but is it safe to assume that the right trigger in shooting isn't really used by itself? For example, you press the left trigger to aim, and then the right trigger to shoot. Yes, you can use the right trigger to fine aim and shoot, but it's difficult to get used to the pressure sensitive thing needed.
Instead of having that, I think it would be best to have an aim from the hip feature where you can be running with your gun and provide a few shots when at close to full speed just to at least keep anyone in front of you at bay. Can also be useful when you steam round a corner and encounter numerous enemies. A few taps of the right trigger keeps them at bay (maybe hitting a few guys) and then you can duck into cover and fine aim your way through.