Pitch and roll are coupled to fwd/back and Left/right respectively. So, you can make it move however you want, but its attitude can't be set independently of its motion. That's a simplification. One consequence is, for example, if you have a fixed camera mounted fwd etc, the angle it looks will correlate with the speed you have it move.

If you are just concerned with moving the center of mass to different locations in space, or have it travel with a specific velocity, you're fine.

This sort of limitation is common vehicles of all sorts; having 4 independent DOF is above average!