Right. If you're facing an enemy and he fires at you, you're simply turning to look away from the bullet, not dodging it.
You shoot where you're pointing, so if you're pointing towards positive Z, your shot will hit Z 10
. If you're pointing towards negative Z, your shot will instead travel to Z -10
You can't tell unless you're looking at the artillery, because there are no landmarks in space. If you move along X it shifts away from the center of your vision along X. In order to keep it in the center, you'd have to rotate the opposite way through X. The same thing applies to the other axes besides W, the depth axis. So if you start out with the enemy aligned on all three dots and then that ceases to be the case, either:
You are rotating
You are moving
The target is moving
See also my post in the 4D Fundamentals topic on strafing:
Really, you think about common sense and past experience with how movement and rotation works in 3D, and test to see if the same applies in 4D. In the first level, perform various motions in the visible axes and watch the effect on the dot markers of the drones. Then try and mimic the effect with the hidden axis, or if you're using two axes, one visible and one hidden.