Once you have both sides adjusted the same, do this simple test.
With NO wind, launch the kite with a good strong pull and watch how high the kite goes with that 1 pull.
Then adjust the bridle to shorten the upper leg, or just wrap the upper bridle line once around the upper spreader connector for this test.
Then redo the launch in NO wind with the same strong pull and see if the kite goes higher or not as high as last time.
By doing this test with several different bridle lengths (longer, shorter, etc), you will find the bridle leg lengths that cause the kite to go the highest with 1 pull in NO wind.
That will be the best bridle settings to provide the most efficient flying which means the kite will fly in the least amount of wind.
I don't know what would cause a kite to fly in a bumpy fashion unless the bridle legs were all too short. That can cause a kite to rock as it flies.
Hope that helps.