Agreed. The Corvettes are a hybrid of fighter and frigate. With the amount of bobbing and weaving that they perform their should be some banking or turning of the ships. This also makes sense when you think about the physics of those turns. One side rapidly accelerating would throw everyone to the other side of the ship. Ships roll slightly to keep the g-forces down and to keep the people in the ship upright and not merging with the bulkhead.
Plus it looks stupid to have a manuverable ship not manuvering.